git-commit-vandalism/run-command.c
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

105 lines
2.0 KiB
C

#include "cache.h"
#include "run-command.h"
#include "exec_cmd.h"
int start_command(struct child_process *cmd)
{
int need_in = !cmd->no_stdin && cmd->in < 0;
int fdin[2];
if (need_in) {
if (pipe(fdin) < 0)
return -ERR_RUN_COMMAND_PIPE;
cmd->in = fdin[1];
cmd->close_in = 1;
}
cmd->pid = fork();
if (cmd->pid < 0) {
if (need_in) {
close(fdin[0]);
close(fdin[1]);
}
return -ERR_RUN_COMMAND_FORK;
}
if (!cmd->pid) {
if (cmd->no_stdin) {
int fd = open("/dev/null", O_RDWR);
dup2(fd, 0);
close(fd);
} else if (need_in) {
dup2(fdin[0], 0);
close(fdin[0]);
close(fdin[1]);
} else if (cmd->in) {
dup2(cmd->in, 0);
close(cmd->in);
}
if (cmd->stdout_to_stderr)
dup2(2, 1);
if (cmd->git_cmd) {
execv_git_cmd(cmd->argv);
} else {
execvp(cmd->argv[0], (char *const*) cmd->argv);
}
die("exec %s failed.", cmd->argv[0]);
}
if (need_in)
close(fdin[0]);
else if (cmd->in)
close(cmd->in);
return 0;
}
int finish_command(struct child_process *cmd)
{
if (cmd->close_in)
close(cmd->in);
for (;;) {
int status, code;
pid_t waiting = waitpid(cmd->pid, &status, 0);
if (waiting < 0) {
if (errno == EINTR)
continue;
error("waitpid failed (%s)", strerror(errno));
return -ERR_RUN_COMMAND_WAITPID;
}
if (waiting != cmd->pid)
return -ERR_RUN_COMMAND_WAITPID_WRONG_PID;
if (WIFSIGNALED(status))
return -ERR_RUN_COMMAND_WAITPID_SIGNAL;
if (!WIFEXITED(status))
return -ERR_RUN_COMMAND_WAITPID_NOEXIT;
code = WEXITSTATUS(status);
if (code)
return -code;
return 0;
}
}
int run_command(struct child_process *cmd)
{
int code = start_command(cmd);
if (code)
return code;
return finish_command(cmd);
}
int run_command_v_opt(const char **argv, int opt)
{
struct child_process cmd;
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;
return run_command(&cmd);
}