Re: [PATCH/RFC] sane_execvp(): ignore non-directory on PATH
From: Jeff King <hidden>
Date: 2016-06-15 22:54:23
On Tue, Jul 31, 2012 at 12:46:13PM -0700, Junio C Hamano wrote:
When you have a non-directory on your PATH, a funny thing happens: $ PATH=$PATH:/bin/sh git foo fatal: cannot exec 'git-foo': Not a directory? Worse yet, as real commands always take precedence over aliases, this behaviour interacts rather badly with them: $ PATH=$PATH:/bin/sh git -c alias.foo=show git foo -s fatal: cannot exec 'git-foo': Not a directory? This is because an ENOTDIR error from the underlying execvp(2) is reported back to the caller of our sane_execvp() wrapper as-is. By translating it to ENOENT, just like the case where we _might_ have the command in an unreadable directory, fixes it. Without an alias, we would get git: 'foo' is not a git command. See 'git --help'. and we use the 'foo' alias when it is available. Signed-off-by: Junio C Hamano <redacted> --- * We can view this as a follow-up to 38f865c (run-command: treat inaccessible directories as ENOENT, 2012-03-30).
Hrm. EACCES is somewhat special, in that the underlying execvp will continue after seeing EACCES, and will only report it back to us if we don't eventually find a good candidate. Is ENOTDIR the same? IOW, If I do: PATH=/bin/cat:/bin ls will I still run "ls"? Testing on my glibc system says "yes", which I think makes this a sane thing to do (if it were not the case and ENOTDIR causes an early return, then that ENOENT is kind of a lie, since we simply don't know the answer).
quoted hunk ↗ jump to hunk
diff --git a/run-command.c b/run-command.c index 805d41f..f9b7db2 100644 --- a/run-command.c +++ b/run-command.c@@ -77,6 +77,8 @@ int sane_execvp(const char *file, char * const argv[]) */ if (errno == EACCES && !strchr(file, '/')) errno = exists_in_PATH(file) ? EACCES : ENOENT; + else if (errno == ENOTDIR && !strchr(file, '/')) + errno = ENOENT; return -1;
Yay. I remember the original 38f865c going through several iterations, and I am glad we took the time to end up with one that made adding this case in so simple. -Peff