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Implement execvpe.
There is some existing practice in other OSes and it's trivial to implement giving the existing code. Fixes BZ #10221.
This commit is contained in:
Ulrich Drepper
221
posix/execvpe.c
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221
posix/execvpe.c
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@ -0,0 +1,221 @@
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/* Copyright (C) 1991,92, 1995-99, 2002, 2004, 2005, 2007, 2009
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Free Software Foundation, Inc.
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This file is part of the GNU C Library.
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The GNU C Library is free software; you can redistribute it and/or
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modify it under the terms of the GNU Lesser General Public
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License as published by the Free Software Foundation; either
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version 2.1 of the License, or (at your option) any later version.
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The GNU C Library is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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Lesser General Public License for more details.
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You should have received a copy of the GNU Lesser General Public
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License along with the GNU C Library; if not, write to the Free
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Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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02111-1307 USA. */
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#include <alloca.h>
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#include <unistd.h>
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#include <stdarg.h>
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#include <stdbool.h>
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#include <stdlib.h>
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#include <string.h>
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#include <errno.h>
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#include <paths.h>
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/* The file is accessible but it is not an executable file. Invoke
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the shell to interpret it as a script. */
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static void
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internal_function
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scripts_argv (const char *file, char *const argv[], int argc, char **new_argv)
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{
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/* Construct an argument list for the shell. */
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new_argv[0] = (char *) _PATH_BSHELL;
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new_argv[1] = (char *) file;
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while (argc > 1)
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{
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new_argv[argc] = argv[argc - 1];
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--argc;
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}
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}
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/* Execute FILE, searching in the `PATH' environment variable if it contains
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no slashes, with arguments ARGV and environment from ENVP. */
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int
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__execvpe (file, argv, envp)
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const char *file;
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char *const argv[];
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char *const envp[];
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{
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if (*file == '\0')
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{
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/* We check the simple case first. */
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__set_errno (ENOENT);
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return -1;
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}
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if (strchr (file, '/') != NULL)
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{
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/* Don't search when it contains a slash. */
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__execve (file, argv, envp);
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if (errno == ENOEXEC)
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{
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/* Count the arguments. */
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int argc = 0;
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while (argv[argc++])
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;
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size_t len = (argc + 1) * sizeof (char *);
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char **script_argv;
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void *ptr = NULL;
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if (__libc_use_alloca (len))
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script_argv = alloca (len);
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else
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script_argv = ptr = malloc (len);
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if (script_argv != NULL)
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{
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scripts_argv (file, argv, argc, script_argv);
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__execve (script_argv[0], script_argv, envp);
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free (ptr);
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}
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}
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}
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else
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{
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size_t pathlen;
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size_t alloclen = 0;
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char *path = getenv ("PATH");
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if (path == NULL)
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{
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pathlen = confstr (_CS_PATH, (char *) NULL, 0);
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alloclen = pathlen + 1;
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}
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else
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pathlen = strlen (path);
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size_t len = strlen (file) + 1;
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alloclen += pathlen + len + 1;
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char *name;
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char *path_malloc = NULL;
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if (__libc_use_alloca (alloclen))
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name = alloca (alloclen);
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else
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{
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path_malloc = name = malloc (alloclen);
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if (name == NULL)
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return -1;
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}
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if (path == NULL)
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{
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/* There is no `PATH' in the environment.
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The default search path is the current directory
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followed by the path `confstr' returns for `_CS_PATH'. */
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path = name + pathlen + len + 1;
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path[0] = ':';
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(void) confstr (_CS_PATH, path + 1, pathlen);
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}
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/* Copy the file name at the top. */
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name = (char *) memcpy (name + pathlen + 1, file, len);
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/* And add the slash. */
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*--name = '/';
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char **script_argv = NULL;
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void *script_argv_malloc = NULL;
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bool got_eacces = false;
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char *p = path;
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do
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{
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char *startp;
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path = p;
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p = __strchrnul (path, ':');
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if (p == path)
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/* Two adjacent colons, or a colon at the beginning or the end
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of `PATH' means to search the current directory. */
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startp = name + 1;
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else
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startp = (char *) memcpy (name - (p - path), path, p - path);
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/* Try to execute this name. If it works, execve will not return. */
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__execve (startp, argv, envp);
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if (errno == ENOEXEC)
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{
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if (script_argv == NULL)
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{
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/* Count the arguments. */
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int argc = 0;
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while (argv[argc++])
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;
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size_t arglen = (argc + 1) * sizeof (char *);
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if (__libc_use_alloca (alloclen + arglen))
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script_argv = alloca (arglen);
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else
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script_argv = script_argv_malloc = malloc (arglen);
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if (script_argv == NULL)
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{
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/* A possible EACCES error is not as important as
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the ENOMEM. */
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got_eacces = false;
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break;
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}
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scripts_argv (startp, argv, argc, script_argv);
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}
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__execve (script_argv[0], script_argv, envp);
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}
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switch (errno)
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{
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case EACCES:
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/* Record the we got a `Permission denied' error. If we end
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up finding no executable we can use, we want to diagnose
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that we did find one but were denied access. */
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got_eacces = true;
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case ENOENT:
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case ESTALE:
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case ENOTDIR:
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/* Those errors indicate the file is missing or not executable
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by us, in which case we want to just try the next path
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directory. */
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case ENODEV:
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case ETIMEDOUT:
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/* Some strange filesystems like AFS return even
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stranger error numbers. They cannot reasonably mean
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anything else so ignore those, too. */
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break;
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default:
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/* Some other error means we found an executable file, but
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something went wrong executing it; return the error to our
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caller. */
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return -1;
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}
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}
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while (*p++ != '\0');
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/* We tried every element and none of them worked. */
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if (got_eacces)
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/* At least one failure was due to permissions, so report that
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error. */
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__set_errno (EACCES);
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free (script_argv_malloc);
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free (path_malloc);
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}
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/* Return the error from the last attempt (probably ENOENT). */
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return -1;
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}
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weak_alias (__execvpe, execvpe)
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