Commit Graph

113 Commits

Author SHA1 Message Date
Shawn O. Pearce
4f41b61148 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 20:57:16 -08:00
Junio C Hamano
030b1a77f7 Merge branch 'js/exec-error-report'
* js/exec-error-report:
  Improve error message when a transport helper was not found
  start_command: detect execvp failures early
  run-command: move wait_or_whine earlier
  start_command: report child process setup errors to the parent's stderr

Conflicts:
	Makefile
2010-01-20 14:44:12 -08:00
Junio C Hamano
3cd02df46a Merge branch 'js/windows'
* js/windows:
  Do not use date.c:tm_to_time_t() from compat/mingw.c
  MSVC: Windows-native implementation for subset of Pthreads API
  MSVC: Fix an "incompatible pointer types" compiler warning
  Windows: avoid the "dup dance" when spawning a child process
  Windows: simplify the pipe(2) implementation
  Windows: boost startup by avoiding a static dependency on shell32.dll
  Windows: disable Python
2010-01-18 18:12:49 -08:00
Johannes Sixt
75301f9015 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>
2010-01-16 16:43:53 -08:00
Johannes Sixt
2b541bf8be 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 10:15:03 -08:00
Johannes Sixt
ab0b41daf6 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 10:05:52 -08:00
Johannes Sixt
a5487ddf0f 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 10:05:34 -08:00
Jeff King
f445644fd2 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>
2010-01-05 23:41:50 -08:00
Jeff King
8dba1e634a 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>
2010-01-01 17:53:46 -08:00
Frank Li
71064e3f86 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>
2009-09-18 20:00:42 -07:00
Frank Li
d7fa500fb5 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>
2009-09-18 20:00:42 -07:00
Frank Li
0d30ad71fa 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>
2009-09-18 20:00:41 -07:00
Johannes Sixt
2affea4125 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 16:33:54 -07:00
Junio C Hamano
08ac69685a Merge branch 'js/run-command-updates'
* js/run-command-updates:
  api-run-command.txt: describe error behavior of run_command functions
  run-command.c: squelch a "use before assignment" warning
  receive-pack: remove unnecessary run_status report
  run_command: report failure to execute the program, but optionally don't
  run_command: encode deadly signal number in the return value
  run_command: report system call errors instead of returning error codes
  run_command: return exit code as positive value
  MinGW: simplify waitpid() emulation macros
2009-08-10 22:14:57 -07:00
David Soria Parra
5a7a3671b7 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 10:04:29 -07:00
Johannes Sixt
c024beb56d 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>
2009-07-06 02:45:50 -07:00
Johannes Sixt
b99d5f40d6 run_command: encode deadly signal number in the return value
We now write the signal number in the error message if the program
terminated by a signal. The negative return value is constructed such that
after truncation to 8 bits it looks like a POSIX shell's $?:

   $ echo 0000 | { git upload-pack .; echo $? >&2; } | :
   error: git-upload-pack died of signal 13
   141

Previously, the exit code was 255 instead of 141.

Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-07-06 02:44:56 -07:00
Johannes Sixt
0ac77ec315 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>
2009-07-06 02:44:49 -07:00
Johannes Sixt
5709e0363a run_command: return exit code as positive value
As a general guideline, functions in git's code return zero to indicate
success and negative values to indicate failure. The run_command family of
functions followed this guideline. But there are actually two different
kinds of failure:

- failures of system calls;

- non-zero exit code of the program that was run.

Usually, a non-zero exit code of the program is a failure and means a
failure to the caller. Except that sometimes it does not. For example, the
exit code of merge programs (e.g. external merge drivers) conveys
information about how the merge failed, and not all exit calls are
actually failures.

Furthermore, the return value of run_command is sometimes used as exit
code by the caller.

This change arranges that the exit code of the program is returned as a
positive value, which can now be regarded as the "result" of the function.
System call failures continue to be reported as negative values.

Signed-off-by: Johannes Sixt <j6t@kdbg.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-07-05 12:16:27 -07:00
Thomas Rast
d824cbba02 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 11:14:53 -07:00
Felipe Contreras
4b25d091ba 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 15:17:31 -07:00
Junio C Hamano
1487eb68f7 Merge branch 'jk/maint-cleanup-after-exec-failure'
* jk/maint-cleanup-after-exec-failure:
  git: use run_command() to execute dashed externals
  run_command(): help callers distinguish errors
  run_command(): handle missing command errors more gracefully
  git: s/run_command/run_builtin/
2009-02-03 00:26:12 -08:00
Jeff King
45c0961c87 run_command(): handle missing command errors more gracefully
When run_command() was asked to run a non-existant command, its behavior
varied depending on the platform:

  - on POSIX systems, we would fork, and then after the execvp call
    failed, we could call die(), which prints a message to stderr and
    exits with code 128.

  - on Windows, we do a PATH lookup, realize the program isn't there, and
    then return ERR_RUN_COMMAND_FORK

The goal of this patch is to make it clear to callers that the specific
error was a missing command. To do this, we will return the error code
ERR_RUN_COMMAND_EXEC, which is already defined in run-command.h, checked
for in several places, but never actually gets set.

The new behavior is:

  - on POSIX systems, we exit the forked process with code 127 (the same
    as the shell uses to report missing commands). The parent process
    recognizes this code and returns an EXEC error. The stderr message is
    silenced, since the caller may be speculatively trying to run a
    command. Instead, we use trace_printf so that somebody interested in
    debugging can see the error that occured.

  - on Windows, we check errno, which is already set correctly by
    mingw_spawnvpe, and report an EXEC error instead of a FORK error

Thus it is safe to speculatively run a command:

  int r = run_command_v_opt(argv, 0);
  if (r == -ERR_RUN_COMMAND_EXEC)
	  /* oops, it wasn't found; try something else */
  else
	  /* we failed for some other reason, error is in r */

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-01-28 14:08:57 -08:00
Stephan Beyer
14e6298f12 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 17:57:15 -08:00
Stephan Beyer
cf94ca8ea9 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>
2009-01-17 17:16:44 -08:00
Stephan Beyer
ae98a0089f 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>
2009-01-17 17:16:24 -08:00
Nanako Shiraishi
7996ff335e run-command.c: remove run_command_v_opt_cd()
This function is not used anywhere.

Johannes Sixt <johannes.sixt@telecom.at>:
> Future callers can use run_command_v_opt_cd_env() instead.

Signed-off-by: Nanako Shiraishi <nanako3@lavabit.com>
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
2008-10-02 18:02:44 -07:00
Junio C Hamano
0208c9611a Merge branch 'jk/pager-swap'
* jk/pager-swap:
  spawn pager via run_command interface
  run-command: add pre-exec callback
2008-08-19 21:42:55 -07:00
Anders Melchiorsen
7d0b18a4da 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 21:46:42 -07:00
Anders Melchiorsen
2c3766f06a 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>
2008-08-03 17:55:40 -07:00
Steffen Prohaska
108ac313f7 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 23:02:11 -07:00
Jeff King
ccf08bc3d0 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>
2008-07-25 21:29:44 -07:00
Junio C Hamano
bed625540a Merge branch 'qq/maint'
* qq/maint:
  run_command(): respect GIT_TRACE

Conflicts:

	run-command.c
2008-07-07 16:42:08 -07:00
Johannes Schindelin
8852f5d704 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 13:16:33 -07:00
Johannes Sixt
7e5d776854 Windows: Implement a custom spawnve().
The problem with Windows's own implementation is that it tries to be
clever when a console program is invoked from a GUI application: In this
case it sometimes automatically allocates a new console window. As a
consequence, the IO channels of the spawned program are directed to the
console, but the invoking application listens on channels that are now
directed to nowhere.

In this implementation we use the lowlevel facilities of CreateProcess(),
which offers a flag to tell the system not to open a console. As a side
effect, only stdin, stdout, and stderr channels will be accessible from
C programs that are spawned. Other channels (file handles, pipe handles,
etc.) are still inherited by the spawned program, but it doesn't get
enough information to access them.

Johannes Schindelin integrated path quoting and unified the various
*execv* and *spawnv* helpers. Eric Raible suggested to also quote '{'.

Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
2008-06-26 08:45:10 +02:00
Johannes Sixt
618ebe9ff9 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>
2008-06-26 08:45:08 +02:00
Johannes Sixt
ba26f296f9 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>
2008-06-23 13:40:31 +02:00
Christian Couder
ce2cf27adc 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 12:18:03 -08:00
Johannes Sixt
c20181e3a3 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>
2008-02-23 11:59:44 -08:00
Johannes Sixt
e72ae28895 start_command(), .in/.out/.err = -1: Callers must close the file descriptor
By setting .in, .out, or .err members of struct child_process to -1, the
callers of start_command() can request that a pipe is allocated that talks
to the child process and one end is returned by replacing -1 with the
file descriptor.

Previously, a flag was set (for .in and .out, but not .err) to signal
finish_command() to close the pipe end that start_command() had handed out,
so it was optional for callers to close the pipe, and many already do so.
Now we make it mandatory to close the pipe.

Signed-off-by: Johannes Sixt <johannes.sixt@telecom.at>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2008-02-23 11:59:44 -08:00
Shawn O. Pearce
b73a439759 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 17:09:55 -08:00
Johannes Sixt
2d22c20830 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>
2007-10-21 01:30:41 -04:00
Johannes Sixt
f3b33f1d22 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>
2007-10-21 01:30:40 -04:00
Alex Riesen
3427b375b5 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 22:38:44 -07:00
Alex Riesen
ee4931486b 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>
2007-05-23 22:38:44 -07:00
Alex Riesen
1568fea01e 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>
2007-05-23 22:38:44 -07:00
Shawn O. Pearce
e4507ae84e 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 23:40:17 -07:00
Shawn O. Pearce
f4bba25bdc 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 23:40:17 -07:00
Shawn O. Pearce
9dc09c7664 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 16:31:35 -07:00
Shawn O. Pearce
4919bf0354 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>
2007-03-11 22:49:40 -07:00
Shawn O. Pearce
ebcb5d16ca 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>
2007-03-11 22:49:37 -07:00
Shawn O. Pearce
f1000898d4 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>
2007-03-11 22:49:34 -07:00
Shawn O. Pearce
afdb269c76 Remove unused run_command variants
We don't actually use these va_list based variants of run_command
anymore.  I'm removing them before I make further improvements.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2007-03-11 22:49:31 -07:00
Shawn O. Pearce
95d3c4f546 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>
2006-12-30 22:22:14 -08:00
Shawn O. Pearce
cd83c74cb3 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>
2006-12-30 22:22:14 -08:00
Shawn O. Pearce
9b0b50936e Remove unnecessary argc parameter from run_command_v.
The argc parameter is never used by the run_command_v family of
functions.  Instead they require that the passed argv[] be NULL
terminated so they can rely on the operating system's execvp
function to correctly pass the arguments to the new process.

Making the caller pass the argc is just confusing, as the caller
could be mislead into believing that the argc might take precendece
over the argv, or that the argv does not need to be NULL terminated.
So goodbye argc.  Don't come back.

Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-12-30 22:22:14 -08:00
Junio C Hamano
85023577a8 simplify inclusion of system header files.
This is a mechanical clean-up of the way *.c files include
system header files.

 (1) sources under compat/, platform sha-1 implementations, and
     xdelta code are exempt from the following rules;

 (2) the first #include must be "git-compat-util.h" or one of
     our own header file that includes it first (e.g. config.h,
     builtin.h, pkt-line.h);

 (3) system headers that are included in "git-compat-util.h"
     need not be included in individual C source files.

 (4) "git-compat-util.h" does not have to include subsystem
     specific header files (e.g. expat.h).

Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-12-20 09:51:35 -08:00
David Rientjes
6f002f984f use appropriate typedefs
Signed-off-by: David Rientjes <rientjes@google.com>
Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-08-15 16:12:09 -07:00
Junio C Hamano
9201c70742 Const tightening.
Mark Wooding noticed there was a type mismatch warning in git.c; this
patch does things slightly differently (mostly tightening const) and
was what I was holding onto, waiting for the setup-revisions change
to be merged into the master branch.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2006-03-05 02:47:29 -08:00
Michal Ostrowski
77cb17e940 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>
2006-01-13 16:49:01 -08:00
Daniel Barkalow
128aed684d 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>
2005-12-07 21:05:39 -08:00
Junio C Hamano
19614330dd receive-pack hooks updates.
The earlier one conflated update and post-update hooks for no
good reason.  Correct that ugly hack.  Now post-update hooks
will take the list of successfully updated refs.

Signed-off-by: Junio C Hamano <junkio@cox.net>
2005-08-02 22:51:09 -07:00
Josef Weidendorfer
b1bf95bba2 [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 23:30:59 -07:00