git/exec_cmd.c
Jeff King 38f865c27d run-command: treat inaccessible directories as ENOENT
When execvp reports EACCES, it can be one of two things:

  1. We found a file to execute, but did not have
     permissions to do so.

  2. We did not have permissions to look in some directory
     in the $PATH.

In the former case, we want to consider this a
permissions problem and report it to the user as such (since
getting this for something like "git foo" is likely a
configuration error).

In the latter case, there is a good chance that the
inaccessible directory does not contain anything of
interest. Reporting "permission denied" is confusing to the
user (and prevents our usual "did you mean...?" lookup). It
also prevents git from trying alias lookup, since we do so
only when an external command does not exist (not when it
exists but has an error).

This patch detects EACCES from execvp, checks whether we are
in case (2), and if so converts errno to ENOENT. This
behavior matches that of "bash" (but not of simpler shells
that use execvp more directly, like "dash").

Test stolen from Junio.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2012-04-05 16:24:13 -07:00

168 lines
3.2 KiB
C

#include "cache.h"
#include "exec_cmd.h"
#include "quote.h"
#define MAX_ARGS 32
static const char *argv_exec_path;
static const char *argv0_path;
const char *system_path(const char *path)
{
#ifdef RUNTIME_PREFIX
static const char *prefix;
#else
static const char *prefix = PREFIX;
#endif
struct strbuf d = STRBUF_INIT;
if (is_absolute_path(path))
return path;
#ifdef RUNTIME_PREFIX
assert(argv0_path);
assert(is_absolute_path(argv0_path));
if (!prefix &&
!(prefix = strip_path_suffix(argv0_path, GIT_EXEC_PATH)) &&
!(prefix = strip_path_suffix(argv0_path, BINDIR)) &&
!(prefix = strip_path_suffix(argv0_path, "git"))) {
prefix = PREFIX;
trace_printf("RUNTIME_PREFIX requested, "
"but prefix computation failed. "
"Using static fallback '%s'.\n", prefix);
}
#endif
strbuf_addf(&d, "%s/%s", prefix, path);
path = strbuf_detach(&d, NULL);
return path;
}
const char *git_extract_argv0_path(const char *argv0)
{
const char *slash;
if (!argv0 || !*argv0)
return NULL;
slash = argv0 + strlen(argv0);
while (argv0 <= slash && !is_dir_sep(*slash))
slash--;
if (slash >= argv0) {
argv0_path = xstrndup(argv0, slash - argv0);
return slash + 1;
}
return argv0;
}
void git_set_argv_exec_path(const char *exec_path)
{
argv_exec_path = exec_path;
/*
* Propagate this setting to external programs.
*/
setenv(EXEC_PATH_ENVIRONMENT, exec_path, 1);
}
/* Returns the highest-priority, location to look for git programs. */
const char *git_exec_path(void)
{
const char *env;
if (argv_exec_path)
return argv_exec_path;
env = getenv(EXEC_PATH_ENVIRONMENT);
if (env && *env) {
return env;
}
return system_path(GIT_EXEC_PATH);
}
static void add_path(struct strbuf *out, const char *path)
{
if (path && *path) {
if (is_absolute_path(path))
strbuf_addstr(out, path);
else
strbuf_addstr(out, absolute_path(path));
strbuf_addch(out, PATH_SEP);
}
}
void setup_path(void)
{
const char *old_path = getenv("PATH");
struct strbuf new_path = STRBUF_INIT;
add_path(&new_path, git_exec_path());
add_path(&new_path, argv0_path);
if (old_path)
strbuf_addstr(&new_path, old_path);
else
strbuf_addstr(&new_path, _PATH_DEFPATH);
setenv("PATH", new_path.buf, 1);
strbuf_release(&new_path);
}
const char **prepare_git_cmd(const char **argv)
{
int argc;
const char **nargv;
for (argc = 0; argv[argc]; argc++)
; /* just counting */
nargv = xmalloc(sizeof(*nargv) * (argc + 2));
nargv[0] = "git";
for (argc = 0; argv[argc]; argc++)
nargv[argc + 1] = argv[argc];
nargv[argc + 1] = NULL;
return nargv;
}
int execv_git_cmd(const char **argv) {
const char **nargv = prepare_git_cmd(argv);
trace_argv_printf(nargv, "trace: exec:");
/* execvp() can only ever return if it fails */
sane_execvp("git", (char **)nargv);
trace_printf("trace: exec failed: %s\n", strerror(errno));
free(nargv);
return -1;
}
int execl_git_cmd(const char *cmd,...)
{
int argc;
const char *argv[MAX_ARGS + 1];
const char *arg;
va_list param;
va_start(param, cmd);
argv[0] = cmd;
argc = 1;
while (argc < MAX_ARGS) {
arg = argv[argc++] = va_arg(param, char *);
if (!arg)
break;
}
va_end(param);
if (MAX_ARGS <= argc)
return error("too many args to run %s", cmd);
argv[argc] = NULL;
return execv_git_cmd(argv);
}