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git-commit-vandalism/run-command.c

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[PATCH] Added hook in git-receive-pack Just before updating a ref, $GIT_DIR/hooks/update refname old-sha1 new-sha1 is called if executable. The hook can decline the ref to be updated by exiting with a non-zero status, or allow it to be updated by exiting with a zero status. The mechanism also allows e.g sending of a mail with pushed commits on the remote repository. Documentation update with an example hook is included. jc: The credits of the basic idea and initial implementation go to Josef, but I ended up rewriting major parts of his patch, so bugs are all mine. Also I changed the semantics for the hook from his original version (which were post-update hook) so that the hook can optionally decline to update the ref, and also can be used to implement the overall cleanups. The latter was primarily to implement a suggestion from Linus that calling update-server-info should be made optional. Signed-off-by: Junio C Hamano <junkio@cox.net>
2005-07-31 21:17:43 +02:00
#include "cache.h"
#include "run-command.h"
Exec git programs without using PATH. The git suite may not be in PATH (and thus programs such as git-send-pack could not exec git-rev-list). Thus there is a need for logic that will locate these programs. Modifying PATH is not desirable as it result in behavior differing from the user's intentions, as we may end up prepending "/usr/bin" to PATH. - git C programs will use exec*_git_cmd() APIs to exec sub-commands. - exec*_git_cmd() will execute a git program by searching for it in the following directories: 1. --exec-path (as used by "git") 2. The GIT_EXEC_PATH environment variable. 3. $(gitexecdir) as set in Makefile (default value $(bindir)). - git wrapper will modify PATH as before to enable shell scripts to invoke "git-foo" commands. Ideally, shell scripts should use the git wrapper to become independent of PATH, and then modifying PATH will not be necessary. [jc: with minor updates after a brief review.] Signed-off-by: Michal Ostrowski <mostrows@watson.ibm.com> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-01-11 03:12:17 +01:00
#include "exec_cmd.h"
[PATCH] Added hook in git-receive-pack Just before updating a ref, $GIT_DIR/hooks/update refname old-sha1 new-sha1 is called if executable. The hook can decline the ref to be updated by exiting with a non-zero status, or allow it to be updated by exiting with a zero status. The mechanism also allows e.g sending of a mail with pushed commits on the remote repository. Documentation update with an example hook is included. jc: The credits of the basic idea and initial implementation go to Josef, but I ended up rewriting major parts of his patch, so bugs are all mine. Also I changed the semantics for the hook from his original version (which were post-update hook) so that the hook can optionally decline to update the ref, and also can be used to implement the overall cleanups. The latter was primarily to implement a suggestion from Linus that calling update-server-info should be made optional. Signed-off-by: Junio C Hamano <junkio@cox.net>
2005-07-31 21:17:43 +02:00
Simplify closing two fds at once in run-command.c I started hacking on a change to add stdout redirection support to the run_command family, but found I was using a lot of close calls on two pipes in an array (such as for pipe). So I'm doing a tiny bit of refactoring first to make the next set of changes clearer. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-03-12 19:37:28 +01:00
static inline void close_pair(int fd[2])
{
close(fd[0]);
close(fd[1]);
}
Windows: avoid the "dup dance" when spawning a child process When stdin, stdout, or stderr must be redirected for a child process that on Windows is spawned using one of the spawn() functions of Microsoft's C runtime, then there is no choice other than to 1. make a backup copy of fd 0,1,2 with dup 2. dup2 the redirection source fd into 0,1,2 3. spawn 4. dup2 the backup back into 0,1,2 5. close the backup copy and the redirection source We used this idiom as well -- but we are not using the spawn() functions anymore! Instead, we have our own implementation. We had hardcoded that stdin, stdout, and stderr of the child process were inherited from the parent's fds 0, 1, and 2. But we can actually specify any fd. With this patch, the fds to inherit are passed from start_command()'s WIN32 section to our spawn implementation. This way, we can avoid the backup copies of the fds. The backup copies were a bug waiting to surface: The OS handles underlying the dup()ed fds were inherited by the child process (but were not associated with a file descriptor in the child). Consequently, the file or pipe represented by the OS handle remained open even after the backup copy was closed in the parent process until the child exited. Since our implementation of pipe() creates non-inheritable OS handles, we still dup() file descriptors in start_command() because dup() happens to create inheritable duplicates. (A nice side effect is that the fd cleanup in start_command is the same for Windows and Unix and remains unchanged.) Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-01-15 21:12:18 +01:00
#ifndef WIN32
Teach run-command to redirect stdout to /dev/null Some run-command callers may wish to just discard any data that is sent to stdout from the child. This is a lot like our existing no_stdin support, we just open /dev/null and duplicate the descriptor into position. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-03-12 19:37:55 +01:00
static inline void dup_devnull(int to)
{
int fd = open("/dev/null", O_RDWR);
dup2(fd, to);
close(fd);
}
Windows: avoid the "dup dance" when spawning a child process When stdin, stdout, or stderr must be redirected for a child process that on Windows is spawned using one of the spawn() functions of Microsoft's C runtime, then there is no choice other than to 1. make a backup copy of fd 0,1,2 with dup 2. dup2 the redirection source fd into 0,1,2 3. spawn 4. dup2 the backup back into 0,1,2 5. close the backup copy and the redirection source We used this idiom as well -- but we are not using the spawn() functions anymore! Instead, we have our own implementation. We had hardcoded that stdin, stdout, and stderr of the child process were inherited from the parent's fds 0, 1, and 2. But we can actually specify any fd. With this patch, the fds to inherit are passed from start_command()'s WIN32 section to our spawn implementation. This way, we can avoid the backup copies of the fds. The backup copies were a bug waiting to surface: The OS handles underlying the dup()ed fds were inherited by the child process (but were not associated with a file descriptor in the child). Consequently, the file or pipe represented by the OS handle remained open even after the backup copy was closed in the parent process until the child exited. Since our implementation of pipe() creates non-inheritable OS handles, we still dup() file descriptors in start_command() because dup() happens to create inheritable duplicates. (A nice side effect is that the fd cleanup in start_command is the same for Windows and Unix and remains unchanged.) Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-01-15 21:12:18 +01:00
#endif
Teach run-command to redirect stdout to /dev/null Some run-command callers may wish to just discard any data that is sent to stdout from the child. This is a lot like our existing no_stdin support, we just open /dev/null and duplicate the descriptor into position. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-03-12 19:37:55 +01:00
run-command: add "use shell" option Many callsites run "sh -c $CMD" to run $CMD. We can make it a little simpler for them by factoring out the munging of argv. For simple cases with no arguments, this doesn't help much, but: 1. For cases with arguments, we save the caller from having to build the appropriate shell snippet. 2. We can later optimize to avoid the shell when there are no metacharacters in the program. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-12-30 11:53:16 +01:00
static const char **prepare_shell_cmd(const char **argv)
{
int argc, nargc = 0;
const char **nargv;
for (argc = 0; argv[argc]; argc++)
; /* just counting */
/* +1 for NULL, +3 for "sh -c" plus extra $0 */
nargv = xmalloc(sizeof(*nargv) * (argc + 1 + 3));
if (argc < 1)
die("BUG: shell command is empty");
run-command: optimize out useless shell calls If there are no metacharacters in the program to be run, we can just skip running the shell entirely and directly exec the program. The metacharacter test is pulled verbatim from launch_editor, which already implements this optimization. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-12-30 11:55:36 +01:00
if (strcspn(argv[0], "|&;<>()$`\\\"' \t\n*?[#~=%") != strlen(argv[0])) {
nargv[nargc++] = "sh";
nargv[nargc++] = "-c";
run-command: add "use shell" option Many callsites run "sh -c $CMD" to run $CMD. We can make it a little simpler for them by factoring out the munging of argv. For simple cases with no arguments, this doesn't help much, but: 1. For cases with arguments, we save the caller from having to build the appropriate shell snippet. 2. We can later optimize to avoid the shell when there are no metacharacters in the program. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-12-30 11:53:16 +01:00
run-command: optimize out useless shell calls If there are no metacharacters in the program to be run, we can just skip running the shell entirely and directly exec the program. The metacharacter test is pulled verbatim from launch_editor, which already implements this optimization. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-12-30 11:55:36 +01:00
if (argc < 2)
nargv[nargc++] = argv[0];
else {
struct strbuf arg0 = STRBUF_INIT;
strbuf_addf(&arg0, "%s \"$@\"", argv[0]);
nargv[nargc++] = strbuf_detach(&arg0, NULL);
}
run-command: add "use shell" option Many callsites run "sh -c $CMD" to run $CMD. We can make it a little simpler for them by factoring out the munging of argv. For simple cases with no arguments, this doesn't help much, but: 1. For cases with arguments, we save the caller from having to build the appropriate shell snippet. 2. We can later optimize to avoid the shell when there are no metacharacters in the program. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-12-30 11:53:16 +01:00
}
for (argc = 0; argv[argc]; argc++)
nargv[nargc++] = argv[argc];
nargv[nargc] = NULL;
return nargv;
}
#ifndef WIN32
static int execv_shell_cmd(const char **argv)
{
const char **nargv = prepare_shell_cmd(argv);
trace_argv_printf(nargv, "trace: exec:");
execvp(nargv[0], (char **)nargv);
free(nargv);
return -1;
}
#endif
start_command: report child process setup errors to the parent's stderr When the child process's environment is set up in start_command(), error messages were written to wherever the parent redirected the child's stderr channel. However, even if the parent redirected the child's stderr, errors during this setup process, including the exec itself, are usually an indication of a problem in the parent's environment. Therefore, the error messages should go to the parent's stderr. Redirection of the child's error messages is usually only used to redirect hook error messages during client-server exchanges. In these cases, hook setup errors could be regarded as information leak. This patch makes a copy of stderr if necessary and uses a special die routine that is used for all die() calls in the child that sends the errors messages to the parent's stderr. The trace call that reported a failed execvp is removed (because it writes to stderr) and replaced by die_errno() with special treatment of ENOENT. The improvement in the error message can be seen with this sequence: mkdir .git/hooks/pre-commit git commit Previously, the error message was error: cannot run .git/hooks/pre-commit: No such file or directory and now it is fatal: cannot exec '.git/hooks/pre-commit': Permission denied Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-01-10 14:07:52 +01:00
#ifndef WIN32
static int child_err = 2;
start_command: detect execvp failures early Previously, failures during execvp could be detected only by finish_command. However, in some situations it is beneficial for the parent process to know earlier that the child process will not run. The idea to use a pipe to signal failures to the parent process and the test case were lifted from patches by Ilari Liusvaara. Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-01-10 14:11:22 +01:00
static int child_notifier = -1;
static void notify_parent(void)
{
write(child_notifier, "", 1);
}
start_command: report child process setup errors to the parent's stderr When the child process's environment is set up in start_command(), error messages were written to wherever the parent redirected the child's stderr channel. However, even if the parent redirected the child's stderr, errors during this setup process, including the exec itself, are usually an indication of a problem in the parent's environment. Therefore, the error messages should go to the parent's stderr. Redirection of the child's error messages is usually only used to redirect hook error messages during client-server exchanges. In these cases, hook setup errors could be regarded as information leak. This patch makes a copy of stderr if necessary and uses a special die routine that is used for all die() calls in the child that sends the errors messages to the parent's stderr. The trace call that reported a failed execvp is removed (because it writes to stderr) and replaced by die_errno() with special treatment of ENOENT. The improvement in the error message can be seen with this sequence: mkdir .git/hooks/pre-commit git commit Previously, the error message was error: cannot run .git/hooks/pre-commit: No such file or directory and now it is fatal: cannot exec '.git/hooks/pre-commit': Permission denied Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-01-10 14:07:52 +01:00
static NORETURN void die_child(const char *err, va_list params)
{
char msg[4096];
int len = vsnprintf(msg, sizeof(msg), err, params);
if (len > sizeof(msg))
len = sizeof(msg);
write(child_err, "fatal: ", 7);
write(child_err, msg, len);
write(child_err, "\n", 1);
exit(128);
}
static inline void set_cloexec(int fd)
{
int flags = fcntl(fd, F_GETFD);
if (flags >= 0)
fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
}
#endif
run-command: move wait_or_whine earlier We want to reuse it from start_command. Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-01-10 14:08:45 +01:00
static int wait_or_whine(pid_t pid, const char *argv0, int silent_exec_failure)
{
int status, code = -1;
pid_t waiting;
int failed_errno = 0;
while ((waiting = waitpid(pid, &status, 0)) < 0 && errno == EINTR)
; /* nothing */
if (waiting < 0) {
failed_errno = errno;
error("waitpid for %s failed: %s", argv0, strerror(errno));
} else if (waiting != pid) {
error("waitpid is confused (%s)", argv0);
} else if (WIFSIGNALED(status)) {
code = WTERMSIG(status);
error("%s died of signal %d", argv0, code);
/*
* This return value is chosen so that code & 0xff
* mimics the exit code that a POSIX shell would report for
* a program that died from this signal.
*/
code -= 128;
} else if (WIFEXITED(status)) {
code = WEXITSTATUS(status);
/*
* Convert special exit code when execvp failed.
*/
if (code == 127) {
code = -1;
failed_errno = ENOENT;
if (!silent_exec_failure)
error("cannot run %s: %s", argv0,
strerror(ENOENT));
}
} else {
error("waitpid is confused (%s)", argv0);
}
errno = failed_errno;
return code;
}
Split run_command into two halves (start/finish) If the calling process wants to send data to stdin of a child process it will need to arrange for a pipe and get the child process running, feed data to it, then wait for the child process to finish. So we split the run function into two halves, allowing callers to first start the child then later finish it. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-03-10 09:28:05 +01:00
int start_command(struct child_process *cmd)
[PATCH] Added hook in git-receive-pack Just before updating a ref, $GIT_DIR/hooks/update refname old-sha1 new-sha1 is called if executable. The hook can decline the ref to be updated by exiting with a non-zero status, or allow it to be updated by exiting with a zero status. The mechanism also allows e.g sending of a mail with pushed commits on the remote repository. Documentation update with an example hook is included. jc: The credits of the basic idea and initial implementation go to Josef, but I ended up rewriting major parts of his patch, so bugs are all mine. Also I changed the semantics for the hook from his original version (which were post-update hook) so that the hook can optionally decline to update the ref, and also can be used to implement the overall cleanups. The latter was primarily to implement a suggestion from Linus that calling update-server-info should be made optional. Signed-off-by: Junio C Hamano <junkio@cox.net>
2005-07-31 21:17:43 +02:00
{
Have start_command() create a pipe to read the stderr of the child. This adds another stanza that allocates a pipe that is connected to the child's stderr and that the caller can read from. In order to request this pipe, the caller sets cmd->err to -1. The implementation is not exactly modeled after the stdout case: For stdout the caller can supply an existing file descriptor, but this facility is nowhere needed in the stderr case. Additionally, the caller is required to close cmd->err. Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at> Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-10-19 21:47:58 +02:00
int need_in, need_out, need_err;
int fdin[2], fdout[2], fderr[2];
run-command.c: squelch a "use before assignment" warning i686-apple-darwin9-gcc-4.0.1 (GCC) 4.0.1 (Apple Inc. build 5490) compiler (and probably others) mistakenly thinks variable failed_errno is used before assigned. Work it around by giving it a fake initialization. Signed-off-by: David Soria Parra <dsp@php.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-08-04 11:28:40 +02:00
int failed_errno = failed_errno;
Teach run_command how to setup a stdin pipe Sometimes callers trying to use run_command to execute a child process will want to setup a pipe or file descriptor to redirect into the child's stdin. This idea is completely stolen from builtin-bundle's fork_with_pipe, written by Johannes Schindelin. All credit (and blame) should lie with Dscho. ;-) Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-03-10 09:28:08 +01:00
start_command(), if .in/.out > 0, closes file descriptors, not the callers Callers of start_command() can set the members .in and .out of struct child_process to a value > 0 to specify that this descriptor is used as the stdin or stdout of the child process. Previously, if start_command() was successful, this descriptor was closed upon return. Here we now make sure that the descriptor is also closed in case of failures. All callers are updated not to close the file descriptor themselves after start_command() was called. Note that earlier run_gpg_verify() of git-verify-tag set .out = 1, which worked because start_command() treated this as a special case, but now this is incorrect because it closes the descriptor. The intent here is to inherit stdout to the child, which is achieved by .out = 0. Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-02-21 23:42:56 +01:00
/*
* In case of errors we must keep the promise to close FDs
* that have been passed in via ->in and ->out.
*/
Teach run-command to redirect stdout to /dev/null Some run-command callers may wish to just discard any data that is sent to stdout from the child. This is a lot like our existing no_stdin support, we just open /dev/null and duplicate the descriptor into position. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-03-12 19:37:55 +01:00
need_in = !cmd->no_stdin && cmd->in < 0;
Teach run_command how to setup a stdin pipe Sometimes callers trying to use run_command to execute a child process will want to setup a pipe or file descriptor to redirect into the child's stdin. This idea is completely stolen from builtin-bundle's fork_with_pipe, written by Johannes Schindelin. All credit (and blame) should lie with Dscho. ;-) Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-03-10 09:28:08 +01:00
if (need_in) {
start_command(), if .in/.out > 0, closes file descriptors, not the callers Callers of start_command() can set the members .in and .out of struct child_process to a value > 0 to specify that this descriptor is used as the stdin or stdout of the child process. Previously, if start_command() was successful, this descriptor was closed upon return. Here we now make sure that the descriptor is also closed in case of failures. All callers are updated not to close the file descriptor themselves after start_command() was called. Note that earlier run_gpg_verify() of git-verify-tag set .out = 1, which worked because start_command() treated this as a special case, but now this is incorrect because it closes the descriptor. The intent here is to inherit stdout to the child, which is achieved by .out = 0. Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-02-21 23:42:56 +01:00
if (pipe(fdin) < 0) {
run_command: report system call errors instead of returning error codes The motivation for this change is that system call failures are serious errors that should be reported to the user, but only few callers took the burden to decode the error codes that the functions returned into error messages. If at all, then only an unspecific error message was given. A prominent example is this: $ git upload-pack . | : fatal: unable to run 'git-upload-pack' In this example, git-upload-pack, the external command invoked through the git wrapper, dies due to SIGPIPE, but the git wrapper does not bother to report the real cause. In fact, this very error message is copied to the syslog if git-daemon's client aborts the connection early. With this change, system call failures are reported immediately after the failure and only a generic failure code is returned to the caller. In the above example the error is now to the point: $ git upload-pack . | : error: git-upload-pack died of signal Note that there is no error report if the invoked program terminated with a non-zero exit code, because it is reasonable to expect that the invoked program has already reported an error. (But many run_command call sites nevertheless write a generic error message.) There was one special return code that was used to identify the case where run_command failed because the requested program could not be exec'd. This special case is now treated like a system call failure with errno set to ENOENT. No error is reported in this case, because the call site in git.c expects this as a normal result. Therefore, the callers that carefully decoded the return value still check for this condition. Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-07-04 21:26:40 +02:00
failed_errno = errno;
start_command(), if .in/.out > 0, closes file descriptors, not the callers Callers of start_command() can set the members .in and .out of struct child_process to a value > 0 to specify that this descriptor is used as the stdin or stdout of the child process. Previously, if start_command() was successful, this descriptor was closed upon return. Here we now make sure that the descriptor is also closed in case of failures. All callers are updated not to close the file descriptor themselves after start_command() was called. Note that earlier run_gpg_verify() of git-verify-tag set .out = 1, which worked because start_command() treated this as a special case, but now this is incorrect because it closes the descriptor. The intent here is to inherit stdout to the child, which is achieved by .out = 0. Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-02-21 23:42:56 +01:00
if (cmd->out > 0)
close(cmd->out);
run_command: report system call errors instead of returning error codes The motivation for this change is that system call failures are serious errors that should be reported to the user, but only few callers took the burden to decode the error codes that the functions returned into error messages. If at all, then only an unspecific error message was given. A prominent example is this: $ git upload-pack . | : fatal: unable to run 'git-upload-pack' In this example, git-upload-pack, the external command invoked through the git wrapper, dies due to SIGPIPE, but the git wrapper does not bother to report the real cause. In fact, this very error message is copied to the syslog if git-daemon's client aborts the connection early. With this change, system call failures are reported immediately after the failure and only a generic failure code is returned to the caller. In the above example the error is now to the point: $ git upload-pack . | : error: git-upload-pack died of signal Note that there is no error report if the invoked program terminated with a non-zero exit code, because it is reasonable to expect that the invoked program has already reported an error. (But many run_command call sites nevertheless write a generic error message.) There was one special return code that was used to identify the case where run_command failed because the requested program could not be exec'd. This special case is now treated like a system call failure with errno set to ENOENT. No error is reported in this case, because the call site in git.c expects this as a normal result. Therefore, the callers that carefully decoded the return value still check for this condition. Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-07-04 21:26:40 +02:00
goto fail_pipe;
start_command(), if .in/.out > 0, closes file descriptors, not the callers Callers of start_command() can set the members .in and .out of struct child_process to a value > 0 to specify that this descriptor is used as the stdin or stdout of the child process. Previously, if start_command() was successful, this descriptor was closed upon return. Here we now make sure that the descriptor is also closed in case of failures. All callers are updated not to close the file descriptor themselves after start_command() was called. Note that earlier run_gpg_verify() of git-verify-tag set .out = 1, which worked because start_command() treated this as a special case, but now this is incorrect because it closes the descriptor. The intent here is to inherit stdout to the child, which is achieved by .out = 0. Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-02-21 23:42:56 +01:00
}
Teach run_command how to setup a stdin pipe Sometimes callers trying to use run_command to execute a child process will want to setup a pipe or file descriptor to redirect into the child's stdin. This idea is completely stolen from builtin-bundle's fork_with_pipe, written by Johannes Schindelin. All credit (and blame) should lie with Dscho. ;-) Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-03-10 09:28:08 +01:00
cmd->in = fdin[1];
}
Teach run-command to redirect stdout to /dev/null Some run-command callers may wish to just discard any data that is sent to stdout from the child. This is a lot like our existing no_stdin support, we just open /dev/null and duplicate the descriptor into position. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-03-12 19:37:55 +01:00
need_out = !cmd->no_stdout
&& !cmd->stdout_to_stderr
&& cmd->out < 0;
Teach run-command about stdout redirection Some potential callers of the run_command family of functions need to control not only the stdin redirection of the child, but also the stdout redirection of the child. This can now be setup much like the already existing stdin redirection. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-03-12 19:37:45 +01:00
if (need_out) {
if (pipe(fdout) < 0) {
run_command: report system call errors instead of returning error codes The motivation for this change is that system call failures are serious errors that should be reported to the user, but only few callers took the burden to decode the error codes that the functions returned into error messages. If at all, then only an unspecific error message was given. A prominent example is this: $ git upload-pack . | : fatal: unable to run 'git-upload-pack' In this example, git-upload-pack, the external command invoked through the git wrapper, dies due to SIGPIPE, but the git wrapper does not bother to report the real cause. In fact, this very error message is copied to the syslog if git-daemon's client aborts the connection early. With this change, system call failures are reported immediately after the failure and only a generic failure code is returned to the caller. In the above example the error is now to the point: $ git upload-pack . | : error: git-upload-pack died of signal Note that there is no error report if the invoked program terminated with a non-zero exit code, because it is reasonable to expect that the invoked program has already reported an error. (But many run_command call sites nevertheless write a generic error message.) There was one special return code that was used to identify the case where run_command failed because the requested program could not be exec'd. This special case is now treated like a system call failure with errno set to ENOENT. No error is reported in this case, because the call site in git.c expects this as a normal result. Therefore, the callers that carefully decoded the return value still check for this condition. Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-07-04 21:26:40 +02:00
failed_errno = errno;
Teach run-command about stdout redirection Some potential callers of the run_command family of functions need to control not only the stdin redirection of the child, but also the stdout redirection of the child. This can now be setup much like the already existing stdin redirection. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-03-12 19:37:45 +01:00
if (need_in)
close_pair(fdin);
start_command(), if .in/.out > 0, closes file descriptors, not the callers Callers of start_command() can set the members .in and .out of struct child_process to a value > 0 to specify that this descriptor is used as the stdin or stdout of the child process. Previously, if start_command() was successful, this descriptor was closed upon return. Here we now make sure that the descriptor is also closed in case of failures. All callers are updated not to close the file descriptor themselves after start_command() was called. Note that earlier run_gpg_verify() of git-verify-tag set .out = 1, which worked because start_command() treated this as a special case, but now this is incorrect because it closes the descriptor. The intent here is to inherit stdout to the child, which is achieved by .out = 0. Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-02-21 23:42:56 +01:00
else if (cmd->in)
close(cmd->in);
run_command: report system call errors instead of returning error codes The motivation for this change is that system call failures are serious errors that should be reported to the user, but only few callers took the burden to decode the error codes that the functions returned into error messages. If at all, then only an unspecific error message was given. A prominent example is this: $ git upload-pack . | : fatal: unable to run 'git-upload-pack' In this example, git-upload-pack, the external command invoked through the git wrapper, dies due to SIGPIPE, but the git wrapper does not bother to report the real cause. In fact, this very error message is copied to the syslog if git-daemon's client aborts the connection early. With this change, system call failures are reported immediately after the failure and only a generic failure code is returned to the caller. In the above example the error is now to the point: $ git upload-pack . | : error: git-upload-pack died of signal Note that there is no error report if the invoked program terminated with a non-zero exit code, because it is reasonable to expect that the invoked program has already reported an error. (But many run_command call sites nevertheless write a generic error message.) There was one special return code that was used to identify the case where run_command failed because the requested program could not be exec'd. This special case is now treated like a system call failure with errno set to ENOENT. No error is reported in this case, because the call site in git.c expects this as a normal result. Therefore, the callers that carefully decoded the return value still check for this condition. Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-07-04 21:26:40 +02:00
goto fail_pipe;
Teach run-command about stdout redirection Some potential callers of the run_command family of functions need to control not only the stdin redirection of the child, but also the stdout redirection of the child. This can now be setup much like the already existing stdin redirection. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-03-12 19:37:45 +01:00
}
cmd->out = fdout[0];
}
run-command: Support sending stderr to /dev/null Some callers may wish to redirect stderr to /dev/null in some contexts, such as if they are executing a command only to get the exit status and don't want users to see whatever output it may produce as a side-effect of computing that exit status. Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-11-11 08:29:37 +01:00
need_err = !cmd->no_stderr && cmd->err < 0;
Have start_command() create a pipe to read the stderr of the child. This adds another stanza that allocates a pipe that is connected to the child's stderr and that the caller can read from. In order to request this pipe, the caller sets cmd->err to -1. The implementation is not exactly modeled after the stdout case: For stdout the caller can supply an existing file descriptor, but this facility is nowhere needed in the stderr case. Additionally, the caller is required to close cmd->err. Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at> Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-10-19 21:47:58 +02:00
if (need_err) {
if (pipe(fderr) < 0) {
run_command: report system call errors instead of returning error codes The motivation for this change is that system call failures are serious errors that should be reported to the user, but only few callers took the burden to decode the error codes that the functions returned into error messages. If at all, then only an unspecific error message was given. A prominent example is this: $ git upload-pack . | : fatal: unable to run 'git-upload-pack' In this example, git-upload-pack, the external command invoked through the git wrapper, dies due to SIGPIPE, but the git wrapper does not bother to report the real cause. In fact, this very error message is copied to the syslog if git-daemon's client aborts the connection early. With this change, system call failures are reported immediately after the failure and only a generic failure code is returned to the caller. In the above example the error is now to the point: $ git upload-pack . | : error: git-upload-pack died of signal Note that there is no error report if the invoked program terminated with a non-zero exit code, because it is reasonable to expect that the invoked program has already reported an error. (But many run_command call sites nevertheless write a generic error message.) There was one special return code that was used to identify the case where run_command failed because the requested program could not be exec'd. This special case is now treated like a system call failure with errno set to ENOENT. No error is reported in this case, because the call site in git.c expects this as a normal result. Therefore, the callers that carefully decoded the return value still check for this condition. Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-07-04 21:26:40 +02:00
failed_errno = errno;
Have start_command() create a pipe to read the stderr of the child. This adds another stanza that allocates a pipe that is connected to the child's stderr and that the caller can read from. In order to request this pipe, the caller sets cmd->err to -1. The implementation is not exactly modeled after the stdout case: For stdout the caller can supply an existing file descriptor, but this facility is nowhere needed in the stderr case. Additionally, the caller is required to close cmd->err. Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at> Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-10-19 21:47:58 +02:00
if (need_in)
close_pair(fdin);
start_command(), if .in/.out > 0, closes file descriptors, not the callers Callers of start_command() can set the members .in and .out of struct child_process to a value > 0 to specify that this descriptor is used as the stdin or stdout of the child process. Previously, if start_command() was successful, this descriptor was closed upon return. Here we now make sure that the descriptor is also closed in case of failures. All callers are updated not to close the file descriptor themselves after start_command() was called. Note that earlier run_gpg_verify() of git-verify-tag set .out = 1, which worked because start_command() treated this as a special case, but now this is incorrect because it closes the descriptor. The intent here is to inherit stdout to the child, which is achieved by .out = 0. Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-02-21 23:42:56 +01:00
else if (cmd->in)
close(cmd->in);
Have start_command() create a pipe to read the stderr of the child. This adds another stanza that allocates a pipe that is connected to the child's stderr and that the caller can read from. In order to request this pipe, the caller sets cmd->err to -1. The implementation is not exactly modeled after the stdout case: For stdout the caller can supply an existing file descriptor, but this facility is nowhere needed in the stderr case. Additionally, the caller is required to close cmd->err. Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at> Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-10-19 21:47:58 +02:00
if (need_out)
close_pair(fdout);
start_command(), if .in/.out > 0, closes file descriptors, not the callers Callers of start_command() can set the members .in and .out of struct child_process to a value > 0 to specify that this descriptor is used as the stdin or stdout of the child process. Previously, if start_command() was successful, this descriptor was closed upon return. Here we now make sure that the descriptor is also closed in case of failures. All callers are updated not to close the file descriptor themselves after start_command() was called. Note that earlier run_gpg_verify() of git-verify-tag set .out = 1, which worked because start_command() treated this as a special case, but now this is incorrect because it closes the descriptor. The intent here is to inherit stdout to the child, which is achieved by .out = 0. Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-02-21 23:42:56 +01:00
else if (cmd->out)
close(cmd->out);
run_command: report system call errors instead of returning error codes The motivation for this change is that system call failures are serious errors that should be reported to the user, but only few callers took the burden to decode the error codes that the functions returned into error messages. If at all, then only an unspecific error message was given. A prominent example is this: $ git upload-pack . | : fatal: unable to run 'git-upload-pack' In this example, git-upload-pack, the external command invoked through the git wrapper, dies due to SIGPIPE, but the git wrapper does not bother to report the real cause. In fact, this very error message is copied to the syslog if git-daemon's client aborts the connection early. With this change, system call failures are reported immediately after the failure and only a generic failure code is returned to the caller. In the above example the error is now to the point: $ git upload-pack . | : error: git-upload-pack died of signal Note that there is no error report if the invoked program terminated with a non-zero exit code, because it is reasonable to expect that the invoked program has already reported an error. (But many run_command call sites nevertheless write a generic error message.) There was one special return code that was used to identify the case where run_command failed because the requested program could not be exec'd. This special case is now treated like a system call failure with errno set to ENOENT. No error is reported in this case, because the call site in git.c expects this as a normal result. Therefore, the callers that carefully decoded the return value still check for this condition. Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-07-04 21:26:40 +02:00
fail_pipe:
error("cannot create pipe for %s: %s",
cmd->argv[0], strerror(failed_errno));
errno = failed_errno;
return -1;
Have start_command() create a pipe to read the stderr of the child. This adds another stanza that allocates a pipe that is connected to the child's stderr and that the caller can read from. In order to request this pipe, the caller sets cmd->err to -1. The implementation is not exactly modeled after the stdout case: For stdout the caller can supply an existing file descriptor, but this facility is nowhere needed in the stderr case. Additionally, the caller is required to close cmd->err. Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at> Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-10-19 21:47:58 +02:00
}
cmd->err = fderr[0];
}
run_command(): respect GIT_TRACE When GIT_TRACE is set, the user is most likely wanting to see an external command that is about to be executed. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-07-07 15:41:34 +02:00
trace_argv_printf(cmd->argv, "trace: run_command:");
Test for WIN32 instead of __MINGW32_ The code which is conditional on MinGW32 is actually conditional on Windows. Use the WIN32 symbol, which is defined by the MINGW32 and MSVC environments, but not by Cygwin. Define SNPRINTF_SIZE_CORR=1 for MSVC too, as its vsnprintf function does not add NUL at the end of the buffer if the result fits the buffer size exactly. Signed-off-by: Frank Li <lznuaa@gmail.com> Signed-off-by: Marius Storm-Olsen <mstormo@gmail.com> Acked-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-09-16 10:20:22 +02:00
#ifndef WIN32
start_command: detect execvp failures early Previously, failures during execvp could be detected only by finish_command. However, in some situations it is beneficial for the parent process to know earlier that the child process will not run. The idea to use a pipe to signal failures to the parent process and the test case were lifted from patches by Ilari Liusvaara. Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-01-10 14:11:22 +01:00
{
int notify_pipe[2];
if (pipe(notify_pipe))
notify_pipe[0] = notify_pipe[1] = -1;
Add output flushing before fork() This adds fflush(NULL) before fork() in start_command(), to keep the generic interface safe. A remaining use of fork() with no flushing is in a comment in show_tree(). Rewrite that comment to use start_command(). Signed-off-by: Anders Melchiorsen <mail@cup.kalibalik.dk> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-08-04 12:18:40 +02:00
fflush(NULL);
Split run_command into two halves (start/finish) If the calling process wants to send data to stdin of a child process it will need to arrange for a pipe and get the child process running, feed data to it, then wait for the child process to finish. So we split the run function into two halves, allowing callers to first start the child then later finish it. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-03-10 09:28:05 +01:00
cmd->pid = fork();
if (!cmd->pid) {
start_command: report child process setup errors to the parent's stderr When the child process's environment is set up in start_command(), error messages were written to wherever the parent redirected the child's stderr channel. However, even if the parent redirected the child's stderr, errors during this setup process, including the exec itself, are usually an indication of a problem in the parent's environment. Therefore, the error messages should go to the parent's stderr. Redirection of the child's error messages is usually only used to redirect hook error messages during client-server exchanges. In these cases, hook setup errors could be regarded as information leak. This patch makes a copy of stderr if necessary and uses a special die routine that is used for all die() calls in the child that sends the errors messages to the parent's stderr. The trace call that reported a failed execvp is removed (because it writes to stderr) and replaced by die_errno() with special treatment of ENOENT. The improvement in the error message can be seen with this sequence: mkdir .git/hooks/pre-commit git commit Previously, the error message was error: cannot run .git/hooks/pre-commit: No such file or directory and now it is fatal: cannot exec '.git/hooks/pre-commit': Permission denied Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-01-10 14:07:52 +01:00
/*
* Redirect the channel to write syscall error messages to
* before redirecting the process's stderr so that all die()
* in subsequent call paths use the parent's stderr.
*/
if (cmd->no_stderr || need_err) {
child_err = dup(2);
set_cloexec(child_err);
}
set_die_routine(die_child);
start_command: detect execvp failures early Previously, failures during execvp could be detected only by finish_command. However, in some situations it is beneficial for the parent process to know earlier that the child process will not run. The idea to use a pipe to signal failures to the parent process and the test case were lifted from patches by Ilari Liusvaara. Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-01-10 14:11:22 +01:00
close(notify_pipe[0]);
set_cloexec(notify_pipe[1]);
child_notifier = notify_pipe[1];
atexit(notify_parent);
Teach run-command to redirect stdout to /dev/null Some run-command callers may wish to just discard any data that is sent to stdout from the child. This is a lot like our existing no_stdin support, we just open /dev/null and duplicate the descriptor into position. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-03-12 19:37:55 +01:00
if (cmd->no_stdin)
dup_devnull(0);
else if (need_in) {
Teach run_command how to setup a stdin pipe Sometimes callers trying to use run_command to execute a child process will want to setup a pipe or file descriptor to redirect into the child's stdin. This idea is completely stolen from builtin-bundle's fork_with_pipe, written by Johannes Schindelin. All credit (and blame) should lie with Dscho. ;-) Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-03-10 09:28:08 +01:00
dup2(fdin[0], 0);
Simplify closing two fds at once in run-command.c I started hacking on a change to add stdout redirection support to the run_command family, but found I was using a lot of close calls on two pipes in an array (such as for pipe). So I'm doing a tiny bit of refactoring first to make the next set of changes clearer. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-03-12 19:37:28 +01:00
close_pair(fdin);
Teach run_command how to setup a stdin pipe Sometimes callers trying to use run_command to execute a child process will want to setup a pipe or file descriptor to redirect into the child's stdin. This idea is completely stolen from builtin-bundle's fork_with_pipe, written by Johannes Schindelin. All credit (and blame) should lie with Dscho. ;-) Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-03-10 09:28:08 +01:00
} else if (cmd->in) {
dup2(cmd->in, 0);
close(cmd->in);
Use /dev/null for update hook stdin. Currently the update hook invoked by receive-pack has its stdin connected to the pushing client. The hook shouldn't attempt to read from this stream, and doing so may consume data that was meant for receive-pack. Instead we should give the update hook /dev/null as its stdin, ensuring that it always receives EOF and doesn't disrupt the protocol if it attempts to read any data. The post-update hook is similar, as it gets invoked with /dev/null on stdin to prevent the hook from reading data from the client. Previously we had invoked it with stdout also connected to /dev/null, throwing away anything on stdout, to prevent client protocol errors. Instead we should redirect stdout to stderr, like we do with the update hook. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-12-31 03:55:22 +01:00
}
Teach run_command how to setup a stdin pipe Sometimes callers trying to use run_command to execute a child process will want to setup a pipe or file descriptor to redirect into the child's stdin. This idea is completely stolen from builtin-bundle's fork_with_pipe, written by Johannes Schindelin. All credit (and blame) should lie with Dscho. ;-) Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-03-10 09:28:08 +01:00
run-command: Redirect stderr to a pipe before redirecting stdout to stderr With this patch, in the 'start_command' function after forking we now take care of stderr in the child process before stdout. This way if 'start_command' is called with a 'child_process' argument like this: .err = -1; .stdout_to_stderr = 1; then stderr will be redirected to a pipe before stdout is redirected to stderr. So we can now get the process' stdout from the pipe (as well as its stderr). Earlier such a call would have redirected stdout to stderr before stderr was itself redirected, and therefore stdout would not have followed stderr, which would not have been very useful anyway. Update documentation in 'api-run-command.txt' accordingly. Signed-off-by: Christian Couder <chriscool@tuxfamily.org> Acked-by: Johannes Sixt <johannes.sixt@telecom.at> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-03-05 08:35:16 +01:00
if (cmd->no_stderr)
dup_devnull(2);
else if (need_err) {
dup2(fderr[1], 2);
close_pair(fderr);
run-command: Allow stderr to be a caller supplied pipe Like .out, .err may now be set to a file descriptor > 0, which is a writable pipe/socket/file that the child's stderr will be redirected into. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-02-05 21:57:37 +01:00
} else if (cmd->err > 1) {
dup2(cmd->err, 2);
close(cmd->err);
run-command: Redirect stderr to a pipe before redirecting stdout to stderr With this patch, in the 'start_command' function after forking we now take care of stderr in the child process before stdout. This way if 'start_command' is called with a 'child_process' argument like this: .err = -1; .stdout_to_stderr = 1; then stderr will be redirected to a pipe before stdout is redirected to stderr. So we can now get the process' stdout from the pipe (as well as its stderr). Earlier such a call would have redirected stdout to stderr before stderr was itself redirected, and therefore stdout would not have followed stderr, which would not have been very useful anyway. Update documentation in 'api-run-command.txt' accordingly. Signed-off-by: Christian Couder <chriscool@tuxfamily.org> Acked-by: Johannes Sixt <johannes.sixt@telecom.at> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-03-05 08:35:16 +01:00
}
Teach run-command to redirect stdout to /dev/null Some run-command callers may wish to just discard any data that is sent to stdout from the child. This is a lot like our existing no_stdin support, we just open /dev/null and duplicate the descriptor into position. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-03-12 19:37:55 +01:00
if (cmd->no_stdout)
dup_devnull(1);
else if (cmd->stdout_to_stderr)
Redirect update hook stdout to stderr. If an update hook outputs to stdout then that output will be sent back over the wire to the push client as though it were part of the git protocol. This tends to cause protocol errors on the client end of the connection, as the hook output is not expected in that context. Most hook developers work around this by making sure their hook outputs everything to stderr. But hooks shouldn't need to perform such special behavior. Instead we can just dup stderr to stdout prior to invoking the update hook. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-12-31 03:55:19 +01:00
dup2(2, 1);
Teach run-command about stdout redirection Some potential callers of the run_command family of functions need to control not only the stdin redirection of the child, but also the stdout redirection of the child. This can now be setup much like the already existing stdin redirection. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-03-12 19:37:45 +01:00
else if (need_out) {
dup2(fdout[1], 1);
close_pair(fdout);
} else if (cmd->out > 1) {
dup2(cmd->out, 1);
close(cmd->out);
}
Add run_command_v_opt_cd: chdir into a directory before exec It can make code simplier (no need to preserve cwd) and safer (no chance the cwd of the current process is accidentally forgotten). Signed-off-by: Alex Riesen <raa.lkml@gmail.com> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-05-22 23:48:23 +02:00
if (cmd->dir && chdir(cmd->dir))
Convert existing die(..., strerror(errno)) to die_errno() Change calls to die(..., strerror(errno)) to use the new die_errno(). In the process, also make slight style adjustments: at least state _something_ about the function that failed (instead of just printing the pathname), and put paths in single quotes. Signed-off-by: Thomas Rast <trast@student.ethz.ch> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-06-27 17:58:46 +02:00
die_errno("exec '%s': cd to '%s' failed", cmd->argv[0],
cmd->dir);
Add ability to specify environment extension to run_command There is no way to specify and override for the environment: there'd be no user for it yet. Signed-off-by: Alex Riesen <raa.lkml@gmail.com> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-05-22 23:48:47 +02:00
if (cmd->env) {
Allow environment variables to be unset in the processes started by run_command To unset a variable, just specify its name, without "=". For example: const char *env[] = {"GIT_DIR=.git", "PWD", NULL}; const char *argv[] = {"git-ls-files", "-s", NULL}; int err = run_command_v_opt_cd_env(argv, RUN_GIT_CMD, ".", env); The PWD will be unset before executing git-ls-files. Signed-off-by: Alex Riesen <raa.lkml@gmail.com> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-05-23 22:21:39 +02:00
for (; *cmd->env; cmd->env++) {
if (strchr(*cmd->env, '='))
Fix a bunch of pointer declarations (codestyle) Essentially; s/type* /type */ as per the coding guidelines. Signed-off-by: Felipe Contreras <felipe.contreras@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-05-01 11:06:36 +02:00
putenv((char *)*cmd->env);
Allow environment variables to be unset in the processes started by run_command To unset a variable, just specify its name, without "=". For example: const char *env[] = {"GIT_DIR=.git", "PWD", NULL}; const char *argv[] = {"git-ls-files", "-s", NULL}; int err = run_command_v_opt_cd_env(argv, RUN_GIT_CMD, ".", env); The PWD will be unset before executing git-ls-files. Signed-off-by: Alex Riesen <raa.lkml@gmail.com> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-05-23 22:21:39 +02:00
else
unsetenv(*cmd->env);
}
Add ability to specify environment extension to run_command There is no way to specify and override for the environment: there'd be no user for it yet. Signed-off-by: Alex Riesen <raa.lkml@gmail.com> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-05-22 23:48:47 +02:00
}
start_command: detect execvp failures early Previously, failures during execvp could be detected only by finish_command. However, in some situations it is beneficial for the parent process to know earlier that the child process will not run. The idea to use a pipe to signal failures to the parent process and the test case were lifted from patches by Ilari Liusvaara. Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-01-10 14:11:22 +01:00
if (cmd->preexec_cb) {
/*
* We cannot predict what the pre-exec callback does.
* Forgo parent notification.
*/
close(child_notifier);
child_notifier = -1;
run-command: add pre-exec callback This is a function provided by the caller which is called _after_ the process is forked, but before the spawned program is executed. On platforms (like mingw) where subprocesses are forked and executed in a single call, the preexec callback is simply ignored. This will be used in the following patch to do some setup for 'less' that must happen in the forked child. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-07-22 09:12:46 +02:00
cmd->preexec_cb();
start_command: detect execvp failures early Previously, failures during execvp could be detected only by finish_command. However, in some situations it is beneficial for the parent process to know earlier that the child process will not run. The idea to use a pipe to signal failures to the parent process and the test case were lifted from patches by Ilari Liusvaara. Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-01-10 14:11:22 +01:00
}
Start defining a more sophisticated run_command There are a number of places where we do some variation of fork()+exec() but we also need to setup redirection in the process, much like what run_command does for us already with its option flags. It would be nice to reuse more of the run_command logic, especially as that non-fork API helps us to port to odd platforms like Win32. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-03-10 09:28:00 +01:00
if (cmd->git_cmd) {
execv_git_cmd(cmd->argv);
run-command: add "use shell" option Many callsites run "sh -c $CMD" to run $CMD. We can make it a little simpler for them by factoring out the munging of argv. For simple cases with no arguments, this doesn't help much, but: 1. For cases with arguments, we save the caller from having to build the appropriate shell snippet. 2. We can later optimize to avoid the shell when there are no metacharacters in the program. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-12-30 11:53:16 +01:00
} else if (cmd->use_shell) {
execv_shell_cmd(cmd->argv);
Exec git programs without using PATH. The git suite may not be in PATH (and thus programs such as git-send-pack could not exec git-rev-list). Thus there is a need for logic that will locate these programs. Modifying PATH is not desirable as it result in behavior differing from the user's intentions, as we may end up prepending "/usr/bin" to PATH. - git C programs will use exec*_git_cmd() APIs to exec sub-commands. - exec*_git_cmd() will execute a git program by searching for it in the following directories: 1. --exec-path (as used by "git") 2. The GIT_EXEC_PATH environment variable. 3. $(gitexecdir) as set in Makefile (default value $(bindir)). - git wrapper will modify PATH as before to enable shell scripts to invoke "git-foo" commands. Ideally, shell scripts should use the git wrapper to become independent of PATH, and then modifying PATH will not be necessary. [jc: with minor updates after a brief review.] Signed-off-by: Michal Ostrowski <mostrows@watson.ibm.com> Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-01-11 03:12:17 +01:00
} else {
Start defining a more sophisticated run_command There are a number of places where we do some variation of fork()+exec() but we also need to setup redirection in the process, much like what run_command does for us already with its option flags. It would be nice to reuse more of the run_command logic, especially as that non-fork API helps us to port to odd platforms like Win32. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-03-10 09:28:00 +01:00
execvp(cmd->argv[0], (char *const*) cmd->argv);
Clean up file descriptors when calling hooks. When calling post-update hook, don't leave stdin and stdout connected to the pushing connection. Signed-off-by: Daniel Barkalow <barkalow@iabervon.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2005-12-08 03:04:38 +01:00
}
start_command: report child process setup errors to the parent's stderr When the child process's environment is set up in start_command(), error messages were written to wherever the parent redirected the child's stderr channel. However, even if the parent redirected the child's stderr, errors during this setup process, including the exec itself, are usually an indication of a problem in the parent's environment. Therefore, the error messages should go to the parent's stderr. Redirection of the child's error messages is usually only used to redirect hook error messages during client-server exchanges. In these cases, hook setup errors could be regarded as information leak. This patch makes a copy of stderr if necessary and uses a special die routine that is used for all die() calls in the child that sends the errors messages to the parent's stderr. The trace call that reported a failed execvp is removed (because it writes to stderr) and replaced by die_errno() with special treatment of ENOENT. The improvement in the error message can be seen with this sequence: mkdir .git/hooks/pre-commit git commit Previously, the error message was error: cannot run .git/hooks/pre-commit: No such file or directory and now it is fatal: cannot exec '.git/hooks/pre-commit': Permission denied Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-01-10 14:07:52 +01:00
/*
* Do not check for cmd->silent_exec_failure; the parent
* process will check it when it sees this exit code.
*/
if (errno == ENOENT)
exit(127);
else
die_errno("cannot exec '%s'", cmd->argv[0]);
[PATCH] Added hook in git-receive-pack Just before updating a ref, $GIT_DIR/hooks/update refname old-sha1 new-sha1 is called if executable. The hook can decline the ref to be updated by exiting with a non-zero status, or allow it to be updated by exiting with a zero status. The mechanism also allows e.g sending of a mail with pushed commits on the remote repository. Documentation update with an example hook is included. jc: The credits of the basic idea and initial implementation go to Josef, but I ended up rewriting major parts of his patch, so bugs are all mine. Also I changed the semantics for the hook from his original version (which were post-update hook) so that the hook can optionally decline to update the ref, and also can be used to implement the overall cleanups. The latter was primarily to implement a suggestion from Linus that calling update-server-info should be made optional. Signed-off-by: Junio C Hamano <junkio@cox.net>
2005-07-31 21:17:43 +02:00
}
run_command: report system call errors instead of returning error codes The motivation for this change is that system call failures are serious errors that should be reported to the user, but only few callers took the burden to decode the error codes that the functions returned into error messages. If at all, then only an unspecific error message was given. A prominent example is this: $ git upload-pack . | : fatal: unable to run 'git-upload-pack' In this example, git-upload-pack, the external command invoked through the git wrapper, dies due to SIGPIPE, but the git wrapper does not bother to report the real cause. In fact, this very error message is copied to the syslog if git-daemon's client aborts the connection early. With this change, system call failures are reported immediately after the failure and only a generic failure code is returned to the caller. In the above example the error is now to the point: $ git upload-pack . | : error: git-upload-pack died of signal Note that there is no error report if the invoked program terminated with a non-zero exit code, because it is reasonable to expect that the invoked program has already reported an error. (But many run_command call sites nevertheless write a generic error message.) There was one special return code that was used to identify the case where run_command failed because the requested program could not be exec'd. This special case is now treated like a system call failure with errno set to ENOENT. No error is reported in this case, because the call site in git.c expects this as a normal result. Therefore, the callers that carefully decoded the return value still check for this condition. Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-07-04 21:26:40 +02:00
if (cmd->pid < 0)
error("cannot fork() for %s: %s", cmd->argv[0],
strerror(failed_errno = errno));
start_command: detect execvp failures early Previously, failures during execvp could be detected only by finish_command. However, in some situations it is beneficial for the parent process to know earlier that the child process will not run. The idea to use a pipe to signal failures to the parent process and the test case were lifted from patches by Ilari Liusvaara. Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-01-10 14:11:22 +01:00
/*
* Wait for child's execvp. If the execvp succeeds (or if fork()
* failed), EOF is seen immediately by the parent. Otherwise, the
* child process sends a single byte.
* Note that use of this infrastructure is completely advisory,
* therefore, we keep error checks minimal.
*/
close(notify_pipe[1]);
if (read(notify_pipe[0], &notify_pipe[1], 1) == 1) {
/*
* At this point we know that fork() succeeded, but execvp()
* failed. Errors have been reported to our stderr.
*/
wait_or_whine(cmd->pid, cmd->argv[0],
cmd->silent_exec_failure);
failed_errno = errno;
cmd->pid = -1;
}
close(notify_pipe[0]);
}
Windows: Implement start_command(). On Windows, we have spawnv() variants to run a child process instead of fork()/exec(). In order to attach pipe ends to stdin, stdout, and stderr, we have to use this idiom: save1 = dup(1); dup2(pipe[1], 1); spawnv(); dup2(save1, 1); close(pipe[1]); assuming that the descriptors created by pipe() are not inheritable. Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
2007-12-07 22:08:59 +01:00
#else
Avoid declaration after statement MSVC does not understand this C99 style. Signed-off-by: Frank Li <lznuaa@gmail.com> Signed-off-by: Marius Storm-Olsen <mstormo@gmail.com> Acked-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-09-16 10:20:17 +02:00
{
Windows: avoid the "dup dance" when spawning a child process When stdin, stdout, or stderr must be redirected for a child process that on Windows is spawned using one of the spawn() functions of Microsoft's C runtime, then there is no choice other than to 1. make a backup copy of fd 0,1,2 with dup 2. dup2 the redirection source fd into 0,1,2 3. spawn 4. dup2 the backup back into 0,1,2 5. close the backup copy and the redirection source We used this idiom as well -- but we are not using the spawn() functions anymore! Instead, we have our own implementation. We had hardcoded that stdin, stdout, and stderr of the child process were inherited from the parent's fds 0, 1, and 2. But we can actually specify any fd. With this patch, the fds to inherit are passed from start_command()'s WIN32 section to our spawn implementation. This way, we can avoid the backup copies of the fds. The backup copies were a bug waiting to surface: The OS handles underlying the dup()ed fds were inherited by the child process (but were not associated with a file descriptor in the child). Consequently, the file or pipe represented by the OS handle remained open even after the backup copy was closed in the parent process until the child exited. Since our implementation of pipe() creates non-inheritable OS handles, we still dup() file descriptors in start_command() because dup() happens to create inheritable duplicates. (A nice side effect is that the fd cleanup in start_command is the same for Windows and Unix and remains unchanged.) Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-01-15 21:12:18 +01:00
int fhin = 0, fhout = 1, fherr = 2;
run-command (Windows): Run dashless "git <cmd>" We prefer running the dashless form, and POSIX side already does so; we should use it in MinGW's start_command(), too. Signed-off-by: Steffen Prohaska <prohaska@zib.de> Acked-by: Johannes Sixt <johannes.sixt@telecom.at> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-07-28 07:50:28 +02:00
const char **sargv = cmd->argv;
Windows: Implement start_command(). On Windows, we have spawnv() variants to run a child process instead of fork()/exec(). In order to attach pipe ends to stdin, stdout, and stderr, we have to use this idiom: save1 = dup(1); dup2(pipe[1], 1); spawnv(); dup2(save1, 1); close(pipe[1]); assuming that the descriptors created by pipe() are not inheritable. Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
2007-12-07 22:08:59 +01:00
char **env = environ;
Windows: avoid the "dup dance" when spawning a child process When stdin, stdout, or stderr must be redirected for a child process that on Windows is spawned using one of the spawn() functions of Microsoft's C runtime, then there is no choice other than to 1. make a backup copy of fd 0,1,2 with dup 2. dup2 the redirection source fd into 0,1,2 3. spawn 4. dup2 the backup back into 0,1,2 5. close the backup copy and the redirection source We used this idiom as well -- but we are not using the spawn() functions anymore! Instead, we have our own implementation. We had hardcoded that stdin, stdout, and stderr of the child process were inherited from the parent's fds 0, 1, and 2. But we can actually specify any fd. With this patch, the fds to inherit are passed from start_command()'s WIN32 section to our spawn implementation. This way, we can avoid the backup copies of the fds. The backup copies were a bug waiting to surface: The OS handles underlying the dup()ed fds were inherited by the child process (but were not associated with a file descriptor in the child). Consequently, the file or pipe represented by the OS handle remained open even after the backup copy was closed in the parent process until the child exited. Since our implementation of pipe() creates non-inheritable OS handles, we still dup() file descriptors in start_command() because dup() happens to create inheritable duplicates. (A nice side effect is that the fd cleanup in start_command is the same for Windows and Unix and remains unchanged.) Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-01-15 21:12:18 +01:00
if (cmd->no_stdin)
fhin = open("/dev/null", O_RDWR);
else if (need_in)
fhin = dup(fdin[0]);
else if (cmd->in)
fhin = dup(cmd->in);
if (cmd->no_stderr)
fherr = open("/dev/null", O_RDWR);
else if (need_err)
fherr = dup(fderr[1]);
Merge branch 'sp/maint-push-sideband' into sp/push-sideband * sp/maint-push-sideband: receive-pack: Send hook output over side band #2 receive-pack: Wrap status reports inside side-band-64k receive-pack: Refactor how capabilities are shown to the client send-pack: demultiplex a sideband stream with status data run-command: support custom fd-set in async run-command: Allow stderr to be a caller supplied pipe Update git fsck --full short description to mention packs Conflicts: run-command.c
2010-02-06 06:08:53 +01:00
else if (cmd->err > 2)
fherr = dup(cmd->err);
Windows: avoid the "dup dance" when spawning a child process When stdin, stdout, or stderr must be redirected for a child process that on Windows is spawned using one of the spawn() functions of Microsoft's C runtime, then there is no choice other than to 1. make a backup copy of fd 0,1,2 with dup 2. dup2 the redirection source fd into 0,1,2 3. spawn 4. dup2 the backup back into 0,1,2 5. close the backup copy and the redirection source We used this idiom as well -- but we are not using the spawn() functions anymore! Instead, we have our own implementation. We had hardcoded that stdin, stdout, and stderr of the child process were inherited from the parent's fds 0, 1, and 2. But we can actually specify any fd. With this patch, the fds to inherit are passed from start_command()'s WIN32 section to our spawn implementation. This way, we can avoid the backup copies of the fds. The backup copies were a bug waiting to surface: The OS handles underlying the dup()ed fds were inherited by the child process (but were not associated with a file descriptor in the child). Consequently, the file or pipe represented by the OS handle remained open even after the backup copy was closed in the parent process until the child exited. Since our implementation of pipe() creates non-inheritable OS handles, we still dup() file descriptors in start_command() because dup() happens to create inheritable duplicates. (A nice side effect is that the fd cleanup in start_command is the same for Windows and Unix and remains unchanged.) Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-01-15 21:12:18 +01:00
if (cmd->no_stdout)
fhout = open("/dev/null", O_RDWR);
else if (cmd->stdout_to_stderr)
fhout = dup(fherr);
else if (need_out)
fhout = dup(fdout[1]);
else if (cmd->out > 1)
fhout = dup(cmd->out);
Windows: Implement start_command(). On Windows, we have spawnv() variants to run a child process instead of fork()/exec(). In order to attach pipe ends to stdin, stdout, and stderr, we have to use this idiom: save1 = dup(1); dup2(pipe[1], 1); spawnv(); dup2(save1, 1); close(pipe[1]); assuming that the descriptors created by pipe() are not inheritable. Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
2007-12-07 22:08:59 +01:00
if (cmd->dir)
die("chdir in start_command() not implemented");
start_command: do not clobber cmd->env on Windows code path Previously, it would not be possible to call start_command twice for the same struct child_process that has env set. The fix is achieved by moving the loop that modifies the environment block into a helper function. This also allows us to make two other helper functions static. Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-09-11 19:40:08 +02:00
if (cmd->env)
env = make_augmented_environ(cmd->env);
Windows: Implement start_command(). On Windows, we have spawnv() variants to run a child process instead of fork()/exec(). In order to attach pipe ends to stdin, stdout, and stderr, we have to use this idiom: save1 = dup(1); dup2(pipe[1], 1); spawnv(); dup2(save1, 1); close(pipe[1]); assuming that the descriptors created by pipe() are not inheritable. Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
2007-12-07 22:08:59 +01:00
if (cmd->git_cmd) {
run-command (Windows): Run dashless "git <cmd>" We prefer running the dashless form, and POSIX side already does so; we should use it in MinGW's start_command(), too. Signed-off-by: Steffen Prohaska <prohaska@zib.de> Acked-by: Johannes Sixt <johannes.sixt@telecom.at> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-07-28 07:50:28 +02:00
cmd->argv = prepare_git_cmd(cmd->argv);
run-command: add "use shell" option Many callsites run "sh -c $CMD" to run $CMD. We can make it a little simpler for them by factoring out the munging of argv. For simple cases with no arguments, this doesn't help much, but: 1. For cases with arguments, we save the caller from having to build the appropriate shell snippet. 2. We can later optimize to avoid the shell when there are no metacharacters in the program. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-12-30 11:53:16 +01:00
} else if (cmd->use_shell) {
cmd->argv = prepare_shell_cmd(cmd->argv);
Windows: Implement start_command(). On Windows, we have spawnv() variants to run a child process instead of fork()/exec(). In order to attach pipe ends to stdin, stdout, and stderr, we have to use this idiom: save1 = dup(1); dup2(pipe[1], 1); spawnv(); dup2(save1, 1); close(pipe[1]); assuming that the descriptors created by pipe() are not inheritable. Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
2007-12-07 22:08:59 +01:00
}
Windows: avoid the "dup dance" when spawning a child process When stdin, stdout, or stderr must be redirected for a child process that on Windows is spawned using one of the spawn() functions of Microsoft's C runtime, then there is no choice other than to 1. make a backup copy of fd 0,1,2 with dup 2. dup2 the redirection source fd into 0,1,2 3. spawn 4. dup2 the backup back into 0,1,2 5. close the backup copy and the redirection source We used this idiom as well -- but we are not using the spawn() functions anymore! Instead, we have our own implementation. We had hardcoded that stdin, stdout, and stderr of the child process were inherited from the parent's fds 0, 1, and 2. But we can actually specify any fd. With this patch, the fds to inherit are passed from start_command()'s WIN32 section to our spawn implementation. This way, we can avoid the backup copies of the fds. The backup copies were a bug waiting to surface: The OS handles underlying the dup()ed fds were inherited by the child process (but were not associated with a file descriptor in the child). Consequently, the file or pipe represented by the OS handle remained open even after the backup copy was closed in the parent process until the child exited. Since our implementation of pipe() creates non-inheritable OS handles, we still dup() file descriptors in start_command() because dup() happens to create inheritable duplicates. (A nice side effect is that the fd cleanup in start_command is the same for Windows and Unix and remains unchanged.) Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-01-15 21:12:18 +01:00
cmd->pid = mingw_spawnvpe(cmd->argv[0], cmd->argv, env,
fhin, fhout, fherr);
run_command: report system call errors instead of returning error codes The motivation for this change is that system call failures are serious errors that should be reported to the user, but only few callers took the burden to decode the error codes that the functions returned into error messages. If at all, then only an unspecific error message was given. A prominent example is this: $ git upload-pack . | : fatal: unable to run 'git-upload-pack' In this example, git-upload-pack, the external command invoked through the git wrapper, dies due to SIGPIPE, but the git wrapper does not bother to report the real cause. In fact, this very error message is copied to the syslog if git-daemon's client aborts the connection early. With this change, system call failures are reported immediately after the failure and only a generic failure code is returned to the caller. In the above example the error is now to the point: $ git upload-pack . | : error: git-upload-pack died of signal Note that there is no error report if the invoked program terminated with a non-zero exit code, because it is reasonable to expect that the invoked program has already reported an error. (But many run_command call sites nevertheless write a generic error message.) There was one special return code that was used to identify the case where run_command failed because the requested program could not be exec'd. This special case is now treated like a system call failure with errno set to ENOENT. No error is reported in this case, because the call site in git.c expects this as a normal result. Therefore, the callers that carefully decoded the return value still check for this condition. Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-07-04 21:26:40 +02:00
failed_errno = errno;
run_command: report failure to execute the program, but optionally don't In the case where a program was not found, it was still the task of the caller to report an error to the user. Usually, this is an interesting case but only few callers actually reported a specific error (though many call sites report a generic error message regardless of the cause). With this change the error is reported by run_command, but since there is one call site in git.c that does not want that, an option is added to struct child_process, which is used to turn the error off. Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-07-04 21:26:42 +02:00
if (cmd->pid < 0 && (!cmd->silent_exec_failure || errno != ENOENT))
run_command: report system call errors instead of returning error codes The motivation for this change is that system call failures are serious errors that should be reported to the user, but only few callers took the burden to decode the error codes that the functions returned into error messages. If at all, then only an unspecific error message was given. A prominent example is this: $ git upload-pack . | : fatal: unable to run 'git-upload-pack' In this example, git-upload-pack, the external command invoked through the git wrapper, dies due to SIGPIPE, but the git wrapper does not bother to report the real cause. In fact, this very error message is copied to the syslog if git-daemon's client aborts the connection early. With this change, system call failures are reported immediately after the failure and only a generic failure code is returned to the caller. In the above example the error is now to the point: $ git upload-pack . | : error: git-upload-pack died of signal Note that there is no error report if the invoked program terminated with a non-zero exit code, because it is reasonable to expect that the invoked program has already reported an error. (But many run_command call sites nevertheless write a generic error message.) There was one special return code that was used to identify the case where run_command failed because the requested program could not be exec'd. This special case is now treated like a system call failure with errno set to ENOENT. No error is reported in this case, because the call site in git.c expects this as a normal result. Therefore, the callers that carefully decoded the return value still check for this condition. Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-07-04 21:26:40 +02:00
error("cannot spawn %s: %s", cmd->argv[0], strerror(errno));
Windows: Implement start_command(). On Windows, we have spawnv() variants to run a child process instead of fork()/exec(). In order to attach pipe ends to stdin, stdout, and stderr, we have to use this idiom: save1 = dup(1); dup2(pipe[1], 1); spawnv(); dup2(save1, 1); close(pipe[1]); assuming that the descriptors created by pipe() are not inheritable. Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
2007-12-07 22:08:59 +01:00
if (cmd->env)
free_environ(env);
if (cmd->git_cmd)
run-command (Windows): Run dashless "git <cmd>" We prefer running the dashless form, and POSIX side already does so; we should use it in MinGW's start_command(), too. Signed-off-by: Steffen Prohaska <prohaska@zib.de> Acked-by: Johannes Sixt <johannes.sixt@telecom.at> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-07-28 07:50:28 +02:00
free(cmd->argv);
Windows: Implement start_command(). On Windows, we have spawnv() variants to run a child process instead of fork()/exec(). In order to attach pipe ends to stdin, stdout, and stderr, we have to use this idiom: save1 = dup(1); dup2(pipe[1], 1); spawnv(); dup2(save1, 1); close(pipe[1]); assuming that the descriptors created by pipe() are not inheritable. Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
2007-12-07 22:08:59 +01:00
run-command (Windows): Run dashless "git <cmd>" We prefer running the dashless form, and POSIX side already does so; we should use it in MinGW's start_command(), too. Signed-off-by: Steffen Prohaska <prohaska@zib.de> Acked-by: Johannes Sixt <johannes.sixt@telecom.at> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-07-28 07:50:28 +02:00
cmd->argv = sargv;
Windows: avoid the "dup dance" when spawning a child process When stdin, stdout, or stderr must be redirected for a child process that on Windows is spawned using one of the spawn() functions of Microsoft's C runtime, then there is no choice other than to 1. make a backup copy of fd 0,1,2 with dup 2. dup2 the redirection source fd into 0,1,2 3. spawn 4. dup2 the backup back into 0,1,2 5. close the backup copy and the redirection source We used this idiom as well -- but we are not using the spawn() functions anymore! Instead, we have our own implementation. We had hardcoded that stdin, stdout, and stderr of the child process were inherited from the parent's fds 0, 1, and 2. But we can actually specify any fd. With this patch, the fds to inherit are passed from start_command()'s WIN32 section to our spawn implementation. This way, we can avoid the backup copies of the fds. The backup copies were a bug waiting to surface: The OS handles underlying the dup()ed fds were inherited by the child process (but were not associated with a file descriptor in the child). Consequently, the file or pipe represented by the OS handle remained open even after the backup copy was closed in the parent process until the child exited. Since our implementation of pipe() creates non-inheritable OS handles, we still dup() file descriptors in start_command() because dup() happens to create inheritable duplicates. (A nice side effect is that the fd cleanup in start_command is the same for Windows and Unix and remains unchanged.) Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-01-15 21:12:18 +01:00
if (fhin != 0)
close(fhin);
if (fhout != 1)
close(fhout);
if (fherr != 2)
close(fherr);
Avoid declaration after statement MSVC does not understand this C99 style. Signed-off-by: Frank Li <lznuaa@gmail.com> Signed-off-by: Marius Storm-Olsen <mstormo@gmail.com> Acked-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-09-16 10:20:17 +02:00
}
Windows: Implement start_command(). On Windows, we have spawnv() variants to run a child process instead of fork()/exec(). In order to attach pipe ends to stdin, stdout, and stderr, we have to use this idiom: save1 = dup(1); dup2(pipe[1], 1); spawnv(); dup2(save1, 1); close(pipe[1]); assuming that the descriptors created by pipe() are not inheritable. Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
2007-12-07 22:08:59 +01:00
#endif
if (cmd->pid < 0) {
if (need_in)
close_pair(fdin);
else if (cmd->in)
close(cmd->in);
if (need_out)
close_pair(fdout);
else if (cmd->out)
close(cmd->out);
if (need_err)
close_pair(fderr);
run_command: report system call errors instead of returning error codes The motivation for this change is that system call failures are serious errors that should be reported to the user, but only few callers took the burden to decode the error codes that the functions returned into error messages. If at all, then only an unspecific error message was given. A prominent example is this: $ git upload-pack . | : fatal: unable to run 'git-upload-pack' In this example, git-upload-pack, the external command invoked through the git wrapper, dies due to SIGPIPE, but the git wrapper does not bother to report the real cause. In fact, this very error message is copied to the syslog if git-daemon's client aborts the connection early. With this change, system call failures are reported immediately after the failure and only a generic failure code is returned to the caller. In the above example the error is now to the point: $ git upload-pack . | : error: git-upload-pack died of signal Note that there is no error report if the invoked program terminated with a non-zero exit code, because it is reasonable to expect that the invoked program has already reported an error. (But many run_command call sites nevertheless write a generic error message.) There was one special return code that was used to identify the case where run_command failed because the requested program could not be exec'd. This special case is now treated like a system call failure with errno set to ENOENT. No error is reported in this case, because the call site in git.c expects this as a normal result. Therefore, the callers that carefully decoded the return value still check for this condition. Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-07-04 21:26:40 +02:00
errno = failed_errno;
return -1;
Windows: Implement start_command(). On Windows, we have spawnv() variants to run a child process instead of fork()/exec(). In order to attach pipe ends to stdin, stdout, and stderr, we have to use this idiom: save1 = dup(1); dup2(pipe[1], 1); spawnv(); dup2(save1, 1); close(pipe[1]); assuming that the descriptors created by pipe() are not inheritable. Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
2007-12-07 22:08:59 +01:00
}
Teach run_command how to setup a stdin pipe Sometimes callers trying to use run_command to execute a child process will want to setup a pipe or file descriptor to redirect into the child's stdin. This idea is completely stolen from builtin-bundle's fork_with_pipe, written by Johannes Schindelin. All credit (and blame) should lie with Dscho. ;-) Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-03-10 09:28:08 +01:00
if (need_in)
close(fdin[0]);
else if (cmd->in)
close(cmd->in);
Teach run-command about stdout redirection Some potential callers of the run_command family of functions need to control not only the stdin redirection of the child, but also the stdout redirection of the child. This can now be setup much like the already existing stdin redirection. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-03-12 19:37:45 +01:00
if (need_out)
close(fdout[1]);
start_command(), if .in/.out > 0, closes file descriptors, not the callers Callers of start_command() can set the members .in and .out of struct child_process to a value > 0 to specify that this descriptor is used as the stdin or stdout of the child process. Previously, if start_command() was successful, this descriptor was closed upon return. Here we now make sure that the descriptor is also closed in case of failures. All callers are updated not to close the file descriptor themselves after start_command() was called. Note that earlier run_gpg_verify() of git-verify-tag set .out = 1, which worked because start_command() treated this as a special case, but now this is incorrect because it closes the descriptor. The intent here is to inherit stdout to the child, which is achieved by .out = 0. Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-02-21 23:42:56 +01:00
else if (cmd->out)
Teach run-command about stdout redirection Some potential callers of the run_command family of functions need to control not only the stdin redirection of the child, but also the stdout redirection of the child. This can now be setup much like the already existing stdin redirection. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-03-12 19:37:45 +01:00
close(cmd->out);
Have start_command() create a pipe to read the stderr of the child. This adds another stanza that allocates a pipe that is connected to the child's stderr and that the caller can read from. In order to request this pipe, the caller sets cmd->err to -1. The implementation is not exactly modeled after the stdout case: For stdout the caller can supply an existing file descriptor, but this facility is nowhere needed in the stderr case. Additionally, the caller is required to close cmd->err. Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at> Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-10-19 21:47:58 +02:00
if (need_err)
close(fderr[1]);
run-command: Allow stderr to be a caller supplied pipe Like .out, .err may now be set to a file descriptor > 0, which is a writable pipe/socket/file that the child's stderr will be redirected into. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-02-05 21:57:37 +01:00
else if (cmd->err)
close(cmd->err);
Have start_command() create a pipe to read the stderr of the child. This adds another stanza that allocates a pipe that is connected to the child's stderr and that the caller can read from. In order to request this pipe, the caller sets cmd->err to -1. The implementation is not exactly modeled after the stdout case: For stdout the caller can supply an existing file descriptor, but this facility is nowhere needed in the stderr case. Additionally, the caller is required to close cmd->err. Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at> Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-10-19 21:47:58 +02:00
Split run_command into two halves (start/finish) If the calling process wants to send data to stdin of a child process it will need to arrange for a pipe and get the child process running, feed data to it, then wait for the child process to finish. So we split the run function into two halves, allowing callers to first start the child then later finish it. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-03-10 09:28:05 +01:00
return 0;
}
Add infrastructure to run a function asynchronously. This adds start_async() and finish_async(), which runs a function asynchronously. Communication with the caller happens only via pipes. For this reason, this implementation forks off a child process that runs the function. [sp: Style nit fixed by removing unnecessary block on if condition inside of start_async()] Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at> Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-10-19 21:48:00 +02:00
int finish_command(struct child_process *cmd)
{
run_command: report failure to execute the program, but optionally don't In the case where a program was not found, it was still the task of the caller to report an error to the user. Usually, this is an interesting case but only few callers actually reported a specific error (though many call sites report a generic error message regardless of the cause). With this change the error is reported by run_command, but since there is one call site in git.c that does not want that, an option is added to struct child_process, which is used to turn the error off. Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-07-04 21:26:42 +02:00
return wait_or_whine(cmd->pid, cmd->argv[0], cmd->silent_exec_failure);
Add infrastructure to run a function asynchronously. This adds start_async() and finish_async(), which runs a function asynchronously. Communication with the caller happens only via pipes. For this reason, this implementation forks off a child process that runs the function. [sp: Style nit fixed by removing unnecessary block on if condition inside of start_async()] Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at> Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-10-19 21:48:00 +02:00
}
Split run_command into two halves (start/finish) If the calling process wants to send data to stdin of a child process it will need to arrange for a pipe and get the child process running, feed data to it, then wait for the child process to finish. So we split the run function into two halves, allowing callers to first start the child then later finish it. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-03-10 09:28:05 +01:00
int run_command(struct child_process *cmd)
{
int code = start_command(cmd);
if (code)
return code;
return finish_command(cmd);
}
Add run_command_v_opt_cd: chdir into a directory before exec It can make code simplier (no need to preserve cwd) and safer (no chance the cwd of the current process is accidentally forgotten). Signed-off-by: Alex Riesen <raa.lkml@gmail.com> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-05-22 23:48:23 +02:00
static void prepare_run_command_v_opt(struct child_process *cmd,
Add ability to specify environment extension to run_command There is no way to specify and override for the environment: there'd be no user for it yet. Signed-off-by: Alex Riesen <raa.lkml@gmail.com> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-05-22 23:48:47 +02:00
const char **argv,
int opt)
Add run_command_v_opt_cd: chdir into a directory before exec It can make code simplier (no need to preserve cwd) and safer (no chance the cwd of the current process is accidentally forgotten). Signed-off-by: Alex Riesen <raa.lkml@gmail.com> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-05-22 23:48:23 +02:00
{
memset(cmd, 0, sizeof(*cmd));
cmd->argv = argv;
cmd->no_stdin = opt & RUN_COMMAND_NO_STDIN ? 1 : 0;
cmd->git_cmd = opt & RUN_GIT_CMD ? 1 : 0;
cmd->stdout_to_stderr = opt & RUN_COMMAND_STDOUT_TO_STDERR ? 1 : 0;
run_command: report failure to execute the program, but optionally don't In the case where a program was not found, it was still the task of the caller to report an error to the user. Usually, this is an interesting case but only few callers actually reported a specific error (though many call sites report a generic error message regardless of the cause). With this change the error is reported by run_command, but since there is one call site in git.c that does not want that, an option is added to struct child_process, which is used to turn the error off. Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-07-04 21:26:42 +02:00
cmd->silent_exec_failure = opt & RUN_SILENT_EXEC_FAILURE ? 1 : 0;
run-command: add "use shell" option Many callsites run "sh -c $CMD" to run $CMD. We can make it a little simpler for them by factoring out the munging of argv. For simple cases with no arguments, this doesn't help much, but: 1. For cases with arguments, we save the caller from having to build the appropriate shell snippet. 2. We can later optimize to avoid the shell when there are no metacharacters in the program. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-12-30 11:53:16 +01:00
cmd->use_shell = opt & RUN_USING_SHELL ? 1 : 0;
Add run_command_v_opt_cd: chdir into a directory before exec It can make code simplier (no need to preserve cwd) and safer (no chance the cwd of the current process is accidentally forgotten). Signed-off-by: Alex Riesen <raa.lkml@gmail.com> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-05-22 23:48:23 +02:00
}
Start defining a more sophisticated run_command There are a number of places where we do some variation of fork()+exec() but we also need to setup redirection in the process, much like what run_command does for us already with its option flags. It would be nice to reuse more of the run_command logic, especially as that non-fork API helps us to port to odd platforms like Win32. Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-03-10 09:28:00 +01:00
int run_command_v_opt(const char **argv, int opt)
{
struct child_process cmd;
Add run_command_v_opt_cd: chdir into a directory before exec It can make code simplier (no need to preserve cwd) and safer (no chance the cwd of the current process is accidentally forgotten). Signed-off-by: Alex Riesen <raa.lkml@gmail.com> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-05-22 23:48:23 +02:00
prepare_run_command_v_opt(&cmd, argv, opt);
return run_command(&cmd);
}
Add ability to specify environment extension to run_command There is no way to specify and override for the environment: there'd be no user for it yet. Signed-off-by: Alex Riesen <raa.lkml@gmail.com> Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-05-22 23:48:47 +02:00
int run_command_v_opt_cd_env(const char **argv, int opt, const char *dir, const char *const *env)
{
struct child_process cmd;
prepare_run_command_v_opt(&cmd, argv, opt);
cmd.dir = dir;
cmd.env = env;
return run_command(&cmd);
}
Add infrastructure to run a function asynchronously. This adds start_async() and finish_async(), which runs a function asynchronously. Communication with the caller happens only via pipes. For this reason, this implementation forks off a child process that runs the function. [sp: Style nit fixed by removing unnecessary block on if condition inside of start_async()] Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at> Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-10-19 21:48:00 +02:00
Test for WIN32 instead of __MINGW32_ The code which is conditional on MinGW32 is actually conditional on Windows. Use the WIN32 symbol, which is defined by the MINGW32 and MSVC environments, but not by Cygwin. Define SNPRINTF_SIZE_CORR=1 for MSVC too, as its vsnprintf function does not add NUL at the end of the buffer if the result fits the buffer size exactly. Signed-off-by: Frank Li <lznuaa@gmail.com> Signed-off-by: Marius Storm-Olsen <mstormo@gmail.com> Acked-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-09-16 10:20:22 +02:00
#ifdef WIN32
Fix __stdcall placement and function prototype MSVC requires __stdcall to be between the functions return value and the function name, and that the function pointer type is in the form of return_type (WINAPI *function_name)(arguments...) Signed-off-by: Frank Li <lznuaa@gmail.com> Signed-off-by: Marius Storm-Olsen <mstormo@gmail.com> Acked-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-09-16 10:20:21 +02:00
static unsigned __stdcall run_thread(void *data)
Windows: Implement asynchronous functions as threads. In upload-pack we must explicitly close the output channel of rev-list. (On Unix, the channel is closed automatically because process that runs rev-list terminates.) Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
2007-12-08 22:19:14 +01:00
{
struct async *async = data;
run-command: support custom fd-set in async This patch adds the possibility to supply a set of non-0 file descriptors for async process communication instead of the default-created pipe. Additionally, we now support bi-directional communiction with the async procedure, by giving the async function both read and write file descriptors. To retain compatiblity and similar "API feel" with start_command, we require start_async callers to set .out = -1 to get a readable file descriptor. If either of .in or .out is 0, we supply no file descriptor to the async process. [sp: Note: Erik started this patch, and a huge bulk of it is his work. All bugs were introduced later by Shawn.] Signed-off-by: Erik Faye-Lund <kusmabite@gmail.com> Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-02-05 21:57:38 +01:00
return async->proc(async->proc_in, async->proc_out, async->data);
Windows: Implement asynchronous functions as threads. In upload-pack we must explicitly close the output channel of rev-list. (On Unix, the channel is closed automatically because process that runs rev-list terminates.) Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
2007-12-08 22:19:14 +01:00
}
#endif
Add infrastructure to run a function asynchronously. This adds start_async() and finish_async(), which runs a function asynchronously. Communication with the caller happens only via pipes. For this reason, this implementation forks off a child process that runs the function. [sp: Style nit fixed by removing unnecessary block on if condition inside of start_async()] Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at> Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-10-19 21:48:00 +02:00
int start_async(struct async *async)
{
run-command: support custom fd-set in async This patch adds the possibility to supply a set of non-0 file descriptors for async process communication instead of the default-created pipe. Additionally, we now support bi-directional communiction with the async procedure, by giving the async function both read and write file descriptors. To retain compatiblity and similar "API feel" with start_command, we require start_async callers to set .out = -1 to get a readable file descriptor. If either of .in or .out is 0, we supply no file descriptor to the async process. [sp: Note: Erik started this patch, and a huge bulk of it is his work. All bugs were introduced later by Shawn.] Signed-off-by: Erik Faye-Lund <kusmabite@gmail.com> Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-02-05 21:57:38 +01:00
int need_in, need_out;
int fdin[2], fdout[2];
int proc_in, proc_out;
Add infrastructure to run a function asynchronously. This adds start_async() and finish_async(), which runs a function asynchronously. Communication with the caller happens only via pipes. For this reason, this implementation forks off a child process that runs the function. [sp: Style nit fixed by removing unnecessary block on if condition inside of start_async()] Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at> Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-10-19 21:48:00 +02:00
run-command: support custom fd-set in async This patch adds the possibility to supply a set of non-0 file descriptors for async process communication instead of the default-created pipe. Additionally, we now support bi-directional communiction with the async procedure, by giving the async function both read and write file descriptors. To retain compatiblity and similar "API feel" with start_command, we require start_async callers to set .out = -1 to get a readable file descriptor. If either of .in or .out is 0, we supply no file descriptor to the async process. [sp: Note: Erik started this patch, and a huge bulk of it is his work. All bugs were introduced later by Shawn.] Signed-off-by: Erik Faye-Lund <kusmabite@gmail.com> Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-02-05 21:57:38 +01:00
need_in = async->in < 0;
if (need_in) {
if (pipe(fdin) < 0) {
if (async->out > 0)
close(async->out);
return error("cannot create pipe: %s", strerror(errno));
}
async->in = fdin[1];
}
need_out = async->out < 0;
if (need_out) {
if (pipe(fdout) < 0) {
if (need_in)
close_pair(fdin);
else if (async->in)
close(async->in);
return error("cannot create pipe: %s", strerror(errno));
}
async->out = fdout[0];
}
if (need_in)
proc_in = fdin[0];
else if (async->in)
proc_in = async->in;
else
proc_in = -1;
if (need_out)
proc_out = fdout[1];
else if (async->out)
proc_out = async->out;
else
proc_out = -1;
Add infrastructure to run a function asynchronously. This adds start_async() and finish_async(), which runs a function asynchronously. Communication with the caller happens only via pipes. For this reason, this implementation forks off a child process that runs the function. [sp: Style nit fixed by removing unnecessary block on if condition inside of start_async()] Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at> Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-10-19 21:48:00 +02:00
Test for WIN32 instead of __MINGW32_ The code which is conditional on MinGW32 is actually conditional on Windows. Use the WIN32 symbol, which is defined by the MINGW32 and MSVC environments, but not by Cygwin. Define SNPRINTF_SIZE_CORR=1 for MSVC too, as its vsnprintf function does not add NUL at the end of the buffer if the result fits the buffer size exactly. Signed-off-by: Frank Li <lznuaa@gmail.com> Signed-off-by: Marius Storm-Olsen <mstormo@gmail.com> Acked-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-09-16 10:20:22 +02:00
#ifndef WIN32
Flush output in start_async This prevents double output in case stdout is redirected. Signed-off-by: Anders Melchiorsen <mail@cup.kalibalik.dk> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-08-04 02:30:03 +02:00
/* Flush stdio before fork() to avoid cloning buffers */
fflush(NULL);
Add infrastructure to run a function asynchronously. This adds start_async() and finish_async(), which runs a function asynchronously. Communication with the caller happens only via pipes. For this reason, this implementation forks off a child process that runs the function. [sp: Style nit fixed by removing unnecessary block on if condition inside of start_async()] Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at> Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-10-19 21:48:00 +02:00
async->pid = fork();
if (async->pid < 0) {
error("fork (async) failed: %s", strerror(errno));
run-command: support custom fd-set in async This patch adds the possibility to supply a set of non-0 file descriptors for async process communication instead of the default-created pipe. Additionally, we now support bi-directional communiction with the async procedure, by giving the async function both read and write file descriptors. To retain compatiblity and similar "API feel" with start_command, we require start_async callers to set .out = -1 to get a readable file descriptor. If either of .in or .out is 0, we supply no file descriptor to the async process. [sp: Note: Erik started this patch, and a huge bulk of it is his work. All bugs were introduced later by Shawn.] Signed-off-by: Erik Faye-Lund <kusmabite@gmail.com> Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-02-05 21:57:38 +01:00
goto error;
Add infrastructure to run a function asynchronously. This adds start_async() and finish_async(), which runs a function asynchronously. Communication with the caller happens only via pipes. For this reason, this implementation forks off a child process that runs the function. [sp: Style nit fixed by removing unnecessary block on if condition inside of start_async()] Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at> Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-10-19 21:48:00 +02:00
}
if (!async->pid) {
run-command: support custom fd-set in async This patch adds the possibility to supply a set of non-0 file descriptors for async process communication instead of the default-created pipe. Additionally, we now support bi-directional communiction with the async procedure, by giving the async function both read and write file descriptors. To retain compatiblity and similar "API feel" with start_command, we require start_async callers to set .out = -1 to get a readable file descriptor. If either of .in or .out is 0, we supply no file descriptor to the async process. [sp: Note: Erik started this patch, and a huge bulk of it is his work. All bugs were introduced later by Shawn.] Signed-off-by: Erik Faye-Lund <kusmabite@gmail.com> Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-02-05 21:57:38 +01:00
if (need_in)
close(fdin[1]);
if (need_out)
close(fdout[0]);
exit(!!async->proc(proc_in, proc_out, async->data));
Add infrastructure to run a function asynchronously. This adds start_async() and finish_async(), which runs a function asynchronously. Communication with the caller happens only via pipes. For this reason, this implementation forks off a child process that runs the function. [sp: Style nit fixed by removing unnecessary block on if condition inside of start_async()] Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at> Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-10-19 21:48:00 +02:00
}
run-command: support custom fd-set in async This patch adds the possibility to supply a set of non-0 file descriptors for async process communication instead of the default-created pipe. Additionally, we now support bi-directional communiction with the async procedure, by giving the async function both read and write file descriptors. To retain compatiblity and similar "API feel" with start_command, we require start_async callers to set .out = -1 to get a readable file descriptor. If either of .in or .out is 0, we supply no file descriptor to the async process. [sp: Note: Erik started this patch, and a huge bulk of it is his work. All bugs were introduced later by Shawn.] Signed-off-by: Erik Faye-Lund <kusmabite@gmail.com> Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-02-05 21:57:38 +01:00
if (need_in)
close(fdin[0]);
else if (async->in)
close(async->in);
if (need_out)
close(fdout[1]);
else if (async->out)
close(async->out);
Windows: Implement asynchronous functions as threads. In upload-pack we must explicitly close the output channel of rev-list. (On Unix, the channel is closed automatically because process that runs rev-list terminates.) Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
2007-12-08 22:19:14 +01:00
#else
run-command: support custom fd-set in async This patch adds the possibility to supply a set of non-0 file descriptors for async process communication instead of the default-created pipe. Additionally, we now support bi-directional communiction with the async procedure, by giving the async function both read and write file descriptors. To retain compatiblity and similar "API feel" with start_command, we require start_async callers to set .out = -1 to get a readable file descriptor. If either of .in or .out is 0, we supply no file descriptor to the async process. [sp: Note: Erik started this patch, and a huge bulk of it is his work. All bugs were introduced later by Shawn.] Signed-off-by: Erik Faye-Lund <kusmabite@gmail.com> Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-02-05 21:57:38 +01:00
async->proc_in = proc_in;
async->proc_out = proc_out;
Windows: Implement asynchronous functions as threads. In upload-pack we must explicitly close the output channel of rev-list. (On Unix, the channel is closed automatically because process that runs rev-list terminates.) Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
2007-12-08 22:19:14 +01:00
async->tid = (HANDLE) _beginthreadex(NULL, 0, run_thread, async, 0, NULL);
if (!async->tid) {
error("cannot create thread: %s", strerror(errno));
run-command: support custom fd-set in async This patch adds the possibility to supply a set of non-0 file descriptors for async process communication instead of the default-created pipe. Additionally, we now support bi-directional communiction with the async procedure, by giving the async function both read and write file descriptors. To retain compatiblity and similar "API feel" with start_command, we require start_async callers to set .out = -1 to get a readable file descriptor. If either of .in or .out is 0, we supply no file descriptor to the async process. [sp: Note: Erik started this patch, and a huge bulk of it is his work. All bugs were introduced later by Shawn.] Signed-off-by: Erik Faye-Lund <kusmabite@gmail.com> Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-02-05 21:57:38 +01:00
goto error;
Windows: Implement asynchronous functions as threads. In upload-pack we must explicitly close the output channel of rev-list. (On Unix, the channel is closed automatically because process that runs rev-list terminates.) Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
2007-12-08 22:19:14 +01:00
}
#endif
Add infrastructure to run a function asynchronously. This adds start_async() and finish_async(), which runs a function asynchronously. Communication with the caller happens only via pipes. For this reason, this implementation forks off a child process that runs the function. [sp: Style nit fixed by removing unnecessary block on if condition inside of start_async()] Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at> Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-10-19 21:48:00 +02:00
return 0;
run-command: support custom fd-set in async This patch adds the possibility to supply a set of non-0 file descriptors for async process communication instead of the default-created pipe. Additionally, we now support bi-directional communiction with the async procedure, by giving the async function both read and write file descriptors. To retain compatiblity and similar "API feel" with start_command, we require start_async callers to set .out = -1 to get a readable file descriptor. If either of .in or .out is 0, we supply no file descriptor to the async process. [sp: Note: Erik started this patch, and a huge bulk of it is his work. All bugs were introduced later by Shawn.] Signed-off-by: Erik Faye-Lund <kusmabite@gmail.com> Signed-off-by: Shawn O. Pearce <spearce@spearce.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-02-05 21:57:38 +01:00
error:
if (need_in)
close_pair(fdin);
else if (async->in)
close(async->in);
if (need_out)
close_pair(fdout);
else if (async->out)
close(async->out);
return -1;
Add infrastructure to run a function asynchronously. This adds start_async() and finish_async(), which runs a function asynchronously. Communication with the caller happens only via pipes. For this reason, this implementation forks off a child process that runs the function. [sp: Style nit fixed by removing unnecessary block on if condition inside of start_async()] Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at> Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-10-19 21:48:00 +02:00
}
int finish_async(struct async *async)
{
Test for WIN32 instead of __MINGW32_ The code which is conditional on MinGW32 is actually conditional on Windows. Use the WIN32 symbol, which is defined by the MINGW32 and MSVC environments, but not by Cygwin. Define SNPRINTF_SIZE_CORR=1 for MSVC too, as its vsnprintf function does not add NUL at the end of the buffer if the result fits the buffer size exactly. Signed-off-by: Frank Li <lznuaa@gmail.com> Signed-off-by: Marius Storm-Olsen <mstormo@gmail.com> Acked-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-09-16 10:20:22 +02:00
#ifndef WIN32
run_command: report failure to execute the program, but optionally don't In the case where a program was not found, it was still the task of the caller to report an error to the user. Usually, this is an interesting case but only few callers actually reported a specific error (though many call sites report a generic error message regardless of the cause). With this change the error is reported by run_command, but since there is one call site in git.c that does not want that, an option is added to struct child_process, which is used to turn the error off. Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-07-04 21:26:42 +02:00
int ret = wait_or_whine(async->pid, "child process", 0);
Windows: Implement asynchronous functions as threads. In upload-pack we must explicitly close the output channel of rev-list. (On Unix, the channel is closed automatically because process that runs rev-list terminates.) Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
2007-12-08 22:19:14 +01:00
#else
DWORD ret = 0;
if (WaitForSingleObject(async->tid, INFINITE) != WAIT_OBJECT_0)
ret = error("waiting for thread failed: %lu", GetLastError());
else if (!GetExitCodeThread(async->tid, &ret))
ret = error("cannot get thread exit code: %lu", GetLastError());
CloseHandle(async->tid);
#endif
Add infrastructure to run a function asynchronously. This adds start_async() and finish_async(), which runs a function asynchronously. Communication with the caller happens only via pipes. For this reason, this implementation forks off a child process that runs the function. [sp: Style nit fixed by removing unnecessary block on if condition inside of start_async()] Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at> Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2007-10-19 21:48:00 +02:00
return ret;
}
Move run_hook() from builtin-commit.c into run-command.c (libgit) A function that runs a hook is used in several Git commands. builtin-commit.c has the one that is most general for cases without piping. The one in builtin-gc.c prints some useful warnings. This patch moves a merged version of these variants into libgit and lets the other builtins use this libified run_hook(). The run_hook() function used in receive-pack.c feeds the standard input of the pre-receive or post-receive hooks. This function is renamed to run_receive_hook() because the libified run_hook() cannot handle this. Mentored-by: Daniel Barkalow <barkalow@iabervon.org> Mentored-by: Christian Couder <chriscool@tuxfamily.org> Signed-off-by: Stephan Beyer <s-beyer@gmx.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-01-16 20:09:59 +01:00
int run_hook(const char *index_file, const char *name, ...)
{
struct child_process hook;
run_hook(): allow more than 9 hook arguments This is done using the ALLOC_GROW macro. Signed-off-by: Stephan Beyer <s-beyer@gmx.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-01-17 04:02:55 +01:00
const char **argv = NULL, *env[2];
Move run_hook() from builtin-commit.c into run-command.c (libgit) A function that runs a hook is used in several Git commands. builtin-commit.c has the one that is most general for cases without piping. The one in builtin-gc.c prints some useful warnings. This patch moves a merged version of these variants into libgit and lets the other builtins use this libified run_hook(). The run_hook() function used in receive-pack.c feeds the standard input of the pre-receive or post-receive hooks. This function is renamed to run_receive_hook() because the libified run_hook() cannot handle this. Mentored-by: Daniel Barkalow <barkalow@iabervon.org> Mentored-by: Christian Couder <chriscool@tuxfamily.org> Signed-off-by: Stephan Beyer <s-beyer@gmx.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-01-16 20:09:59 +01:00
char index[PATH_MAX];
va_list args;
int ret;
run_hook(): allow more than 9 hook arguments This is done using the ALLOC_GROW macro. Signed-off-by: Stephan Beyer <s-beyer@gmx.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-01-17 04:02:55 +01:00
size_t i = 0, alloc = 0;
Move run_hook() from builtin-commit.c into run-command.c (libgit) A function that runs a hook is used in several Git commands. builtin-commit.c has the one that is most general for cases without piping. The one in builtin-gc.c prints some useful warnings. This patch moves a merged version of these variants into libgit and lets the other builtins use this libified run_hook(). The run_hook() function used in receive-pack.c feeds the standard input of the pre-receive or post-receive hooks. This function is renamed to run_receive_hook() because the libified run_hook() cannot handle this. Mentored-by: Daniel Barkalow <barkalow@iabervon.org> Mentored-by: Christian Couder <chriscool@tuxfamily.org> Signed-off-by: Stephan Beyer <s-beyer@gmx.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-01-16 20:09:59 +01:00
run_hook(): check the executability of the hook before filling argv Signed-off-by: Stephan Beyer <s-beyer@gmx.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-01-16 20:10:01 +01:00
if (access(git_path("hooks/%s", name), X_OK) < 0)
return 0;
Move run_hook() from builtin-commit.c into run-command.c (libgit) A function that runs a hook is used in several Git commands. builtin-commit.c has the one that is most general for cases without piping. The one in builtin-gc.c prints some useful warnings. This patch moves a merged version of these variants into libgit and lets the other builtins use this libified run_hook(). The run_hook() function used in receive-pack.c feeds the standard input of the pre-receive or post-receive hooks. This function is renamed to run_receive_hook() because the libified run_hook() cannot handle this. Mentored-by: Daniel Barkalow <barkalow@iabervon.org> Mentored-by: Christian Couder <chriscool@tuxfamily.org> Signed-off-by: Stephan Beyer <s-beyer@gmx.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-01-16 20:09:59 +01:00
va_start(args, name);
run_hook(): allow more than 9 hook arguments This is done using the ALLOC_GROW macro. Signed-off-by: Stephan Beyer <s-beyer@gmx.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-01-17 04:02:55 +01:00
ALLOC_GROW(argv, i + 1, alloc);
argv[i++] = git_path("hooks/%s", name);
while (argv[i-1]) {
ALLOC_GROW(argv, i + 1, alloc);
argv[i++] = va_arg(args, const char *);
}
Move run_hook() from builtin-commit.c into run-command.c (libgit) A function that runs a hook is used in several Git commands. builtin-commit.c has the one that is most general for cases without piping. The one in builtin-gc.c prints some useful warnings. This patch moves a merged version of these variants into libgit and lets the other builtins use this libified run_hook(). The run_hook() function used in receive-pack.c feeds the standard input of the pre-receive or post-receive hooks. This function is renamed to run_receive_hook() because the libified run_hook() cannot handle this. Mentored-by: Daniel Barkalow <barkalow@iabervon.org> Mentored-by: Christian Couder <chriscool@tuxfamily.org> Signed-off-by: Stephan Beyer <s-beyer@gmx.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-01-16 20:09:59 +01:00
va_end(args);
memset(&hook, 0, sizeof(hook));
hook.argv = argv;
hook.no_stdin = 1;
hook.stdout_to_stderr = 1;
if (index_file) {
snprintf(index, sizeof(index), "GIT_INDEX_FILE=%s", index_file);
env[0] = index;
env[1] = NULL;
hook.env = env;
}
run_command: report system call errors instead of returning error codes The motivation for this change is that system call failures are serious errors that should be reported to the user, but only few callers took the burden to decode the error codes that the functions returned into error messages. If at all, then only an unspecific error message was given. A prominent example is this: $ git upload-pack . | : fatal: unable to run 'git-upload-pack' In this example, git-upload-pack, the external command invoked through the git wrapper, dies due to SIGPIPE, but the git wrapper does not bother to report the real cause. In fact, this very error message is copied to the syslog if git-daemon's client aborts the connection early. With this change, system call failures are reported immediately after the failure and only a generic failure code is returned to the caller. In the above example the error is now to the point: $ git upload-pack . | : error: git-upload-pack died of signal Note that there is no error report if the invoked program terminated with a non-zero exit code, because it is reasonable to expect that the invoked program has already reported an error. (But many run_command call sites nevertheless write a generic error message.) There was one special return code that was used to identify the case where run_command failed because the requested program could not be exec'd. This special case is now treated like a system call failure with errno set to ENOENT. No error is reported in this case, because the call site in git.c expects this as a normal result. Therefore, the callers that carefully decoded the return value still check for this condition. Signed-off-by: Johannes Sixt <j6t@kdbg.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-07-04 21:26:40 +02:00
ret = run_command(&hook);
run_hook(): allow more than 9 hook arguments This is done using the ALLOC_GROW macro. Signed-off-by: Stephan Beyer <s-beyer@gmx.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-01-17 04:02:55 +01:00
free(argv);
Move run_hook() from builtin-commit.c into run-command.c (libgit) A function that runs a hook is used in several Git commands. builtin-commit.c has the one that is most general for cases without piping. The one in builtin-gc.c prints some useful warnings. This patch moves a merged version of these variants into libgit and lets the other builtins use this libified run_hook(). The run_hook() function used in receive-pack.c feeds the standard input of the pre-receive or post-receive hooks. This function is renamed to run_receive_hook() because the libified run_hook() cannot handle this. Mentored-by: Daniel Barkalow <barkalow@iabervon.org> Mentored-by: Christian Couder <chriscool@tuxfamily.org> Signed-off-by: Stephan Beyer <s-beyer@gmx.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-01-16 20:09:59 +01:00
return ret;
}
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