Re: [PATCH] When exec'ing sub-commands, fall back on execvp (thePATH)
- From
Scott R Parish <srp@srparish.net>
- Date
- Oct 20, 2007, 08:12 UTC
- Message-ID
- <1192867937.v2.fusewebmail-240137@f>
Yeah, that seems to work fine. The theoretical drawback to this approach is that it could possibly effect the order in which the paths are tried. For instance, if a user did "export GIT_EXEC_PATH=", then the builtin_exec_path wouldn't be tried before the PATH. (i doubt that it would be a problem, but thought i should note it)
sRp
----- Original Message ----- Subject: Re: [PATCH] When exec'ing sub-commands, fall back on execvp (thePATH) Date: Sat, October 20, 2007 0:30 From: "Johannes Schindelin" <Johannes.Schindelin@gmx.de>
Show 34 quoted lines
> Hi,
>
> On Fri, 19 Oct 2007, Scott Parish wrote:
>
> > diff --git a/exec_cmd.c b/exec_cmd.c
> > index 9b74ed2..674c9f3 100644
> > --- a/exec_cmd.c
> > +++ b/exec_cmd.c
> > @@ -34,15 +34,15 @@ int execv_git_cmd(const char **argv)
> > {
> > char git_command[PATH_MAX + 1];
> > int i;
> > + int rc;
> > const char *paths[] = { current_exec_path,
> > getenv(EXEC_PATH_ENVIRONMENT),
> > builtin_exec_path };
> > + const char *tmp;
> > + size_t len;
> >
> > for (i = 0; i < ARRAY_SIZE(paths); ++i) {
> > - size_t len;
> > - int rc;
> > const char *exec_dir = paths[i];
> > - const char *tmp;
> >
> > if (!exec_dir || !*exec_dir) continue;
> >
> > @@ -106,8 +106,26 @@ int execv_git_cmd(const char **argv)
> >
> > argv[0] = tmp;
> > }
> > - return -1;
> >
> > + rc = snprintf(git_command, sizeof(git_command), "git-%s",argv[0]);
> > + if (rc < 0 || rc >= sizeof(git_command) - len) {
> > + fprintf(stderr, "git: command name given is toolong.\n");
Show 54 quoted lines
> > + return -1;
> > + }
> > +
> > + tmp = argv[0];
> > + argv[0] = git_command;
> > +
> > + trace_argv_printf(argv, -1, "trace: exec:");
> > +
> > + /* execve() can only ever return if it fails */
> > + execvp(git_command, (char **)argv);
> > +
> > + trace_printf("trace: exec failed: %s\n", strerror(errno));
> > +
> > + argv[0] = tmp;
> > +
> > + return -1;
> > }
>
> I am not sure that this is elegant enough: Something like this (completely
> untested) might be better:
>
> diff --git a/exec_cmd.c b/exec_cmd.c
> index 9b74ed2..c928f37 100644
> --- a/exec_cmd.c
> +++ b/exec_cmd.c
> @@ -36,7 +36,8 @@ int execv_git_cmd(const char **argv)
> int i;
> const char *paths[] = { current_exec_path,
> getenv(EXEC_PATH_ENVIRONMENT),
> - builtin_exec_path };
> + builtin_exec_path,
> + "" };
>
> for (i = 0; i < ARRAY_SIZE(paths); ++i) {
> size_t len;
> @@ -44,9 +45,12 @@ int execv_git_cmd(const char **argv)
> const char *exec_dir = paths[i];
> const char *tmp;
>
> - if (!exec_dir || !*exec_dir) continue;
> + if (!exec_dir) continue;
>
> - if (*exec_dir != '/') {
> + if (!*exec_dir)
> + /* try PATH */
> + *git_command = '\0';
> + else if (*exec_dir != '/') {
> if (!getcwd(git_command, sizeof(git_command))) {
> fprintf(stderr, "git: cannot determine "
> "current directory: %s\n",
> @@ -81,7 +85,7 @@ int execv_git_cmd(const char **argv)
>
> len = strlen(git_command);
> rc = snprintf(git_command + len, sizeof(git_command) -len,
Show 15 quoted lines
> - "/git-%s", argv[0]);
> + "%sgit-%s", *exec_dir ? "/" : "", argv[0]);
> if (rc < 0 || rc >= sizeof(git_command) - len) {
> fprintf(stderr,
> "git: command name given is too long.\n");
>
> Ciao,
> Dscho
>
> -
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