--- /dev/null
+/* Copyright (C) 2006 by Paolo Giarrusso - modified from glibc' execvp.c.
+ Original copyright notice follows:
+
+ Copyright (C) 1991,92,1995-99,2002,2004 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+#include <unistd.h>
+
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <limits.h>
+
+#ifndef TEST
+#include "um_malloc.h"
+#else
+#include <stdio.h>
+#define um_kmalloc malloc
+#endif
+#include "os.h"
+
+/* Execute FILE, searching in the `PATH' environment variable if it contains
+ no slashes, with arguments ARGV and environment from `environ'. */
+int execvp_noalloc(char *buf, const char *file, char *const argv[])
+{
+ if (*file == '\0') {
+ return -ENOENT;
+ }
+
+ if (strchr (file, '/') != NULL) {
+ /* Don't search when it contains a slash. */
+ execv(file, argv);
+ } else {
+ int got_eacces;
+ size_t len, pathlen;
+ char *name, *p;
+ char *path = getenv("PATH");
+ if (path == NULL)
+ path = ":/bin:/usr/bin";
+
+ len = strlen(file) + 1;
+ pathlen = strlen(path);
+ /* Copy the file name at the top. */
+ name = memcpy(buf + pathlen + 1, file, len);
+ /* And add the slash. */
+ *--name = '/';
+
+ got_eacces = 0;
+ p = path;
+ do {
+ char *startp;
+
+ path = p;
+ //Let's avoid this GNU extension.
+ //p = strchrnul (path, ':');
+ p = strchr(path, ':');
+ if (!p)
+ p = strchr(path, '\0');
+
+ if (p == path)
+ /* Two adjacent colons, or a colon at the beginning or the end
+ of `PATH' means to search the current directory. */
+ startp = name + 1;
+ else
+ startp = memcpy(name - (p - path), path, p - path);
+
+ /* Try to execute this name. If it works, execv will not return. */
+ execv(startp, argv);
+
+ /*
+ if (errno == ENOEXEC) {
+ }
+ */
+
+ switch (errno) {
+ case EACCES:
+ /* Record the we got a `Permission denied' error. If we end
+ up finding no executable we can use, we want to diagnose
+ that we did find one but were denied access. */
+ got_eacces = 1;
+ case ENOENT:
+ case ESTALE:
+ case ENOTDIR:
+ /* Those errors indicate the file is missing or not executable
+ by us, in which case we want to just try the next path
+ directory. */
+ case ENODEV:
+ case ETIMEDOUT:
+ /* Some strange filesystems like AFS return even
+ stranger error numbers. They cannot reasonably mean
+ anything else so ignore those, too. */
+ case ENOEXEC:
+ /* We won't go searching for the shell
+ * if it is not executable - the Linux
+ * kernel already handles this enough,
+ * for us. */
+ break;
+
+ default:
+ /* Some other error means we found an executable file, but
+ something went wrong executing it; return the error to our
+ caller. */
+ return -errno;
+ }
+ } while (*p++ != '\0');
+
+ /* We tried every element and none of them worked. */
+ if (got_eacces)
+ /* At least one failure was due to permissions, so report that
+ error. */
+ return -EACCES;
+ }
+
+ /* Return the error from the last attempt (probably ENOENT). */
+ return -errno;
+}
+#ifdef TEST
+int main(int argc, char**argv)
+{
+ char buf[PATH_MAX];
+ int ret;
+ argc--;
+ if (!argc) {
+ fprintf(stderr, "Not enough arguments\n");
+ return 1;
+ }
+ argv++;
+ if (ret = execvp_noalloc(buf, argv[0], argv)) {
+ errno = -ret;
+ perror("execvp_noalloc");
+ }
+ return 0;
+}
+#endif
git://git.onelab.eu / linux-2.6.git / blobdiff