git/run-command.c
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

74 lines
1.5 KiB
C

#include "cache.h"
#include "run-command.h"
#include <sys/wait.h>
#include "exec_cmd.h"
int run_command_v_opt(int argc, char **argv, int flags)
{
pid_t pid = fork();
if (pid < 0)
return -ERR_RUN_COMMAND_FORK;
if (!pid) {
if (flags & RUN_COMMAND_NO_STDIO) {
int fd = open("/dev/null", O_RDWR);
dup2(fd, 0);
dup2(fd, 1);
close(fd);
}
if (flags & RUN_GIT_CMD) {
execv_git_cmd(argv);
} else {
execvp(argv[0], (char *const*) argv);
}
die("exec %s failed.", argv[0]);
}
for (;;) {
int status, code;
int retval = waitpid(pid, &status, 0);
if (retval < 0) {
if (errno == EINTR)
continue;
error("waitpid failed (%s)", strerror(retval));
return -ERR_RUN_COMMAND_WAITPID;
}
if (retval != 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_v(int argc, char **argv)
{
return run_command_v_opt(argc, argv, 0);
}
int run_command(const char *cmd, ...)
{
int argc;
char *argv[MAX_RUN_COMMAND_ARGS];
const char *arg;
va_list param;
va_start(param, cmd);
argv[0] = (char*) cmd;
argc = 1;
while (argc < MAX_RUN_COMMAND_ARGS) {
arg = argv[argc++] = va_arg(param, char *);
if (!arg)
break;
}
va_end(param);
if (MAX_RUN_COMMAND_ARGS <= argc)
return error("too many args to run %s", cmd);
return run_command_v_opt(argc, argv, 0);
}