busybox

/* vi: set sw=4 ts=4: */

/*

 * Mini xargs implementation for busybox

 * Options are supported: "-prtx -n max_arg -s max_chars -e[ouf_str]"

 *

 * (C) 2002,2003 by Vladimir Oleynik <dzo@simtreas.ru>

 *

 * Special thanks

 * - Mark Whitley and Glenn McGrath for stimulus to rewrite :)

 * - Mike Rendell <michael@cs.mun.ca>

 * and David MacKenzie <djm@gnu.ai.mit.edu>.

 *

 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.

 *

 * xargs is described in the Single Unix Specification v3 at

 * http://www.opengroup.org/onlinepubs/007904975/utilities/xargs.html

 *

 */

​

#include "busybox.h"

​

/* COMPAT:  SYSV version defaults size (and has a max value of) to 470.

   We try to make it as large as possible. */

#if !defined(ARG_MAX) && defined(_SC_ARG_MAX)

#define ARG_MAX sysconf (_SC_ARG_MAX)

#endif

#ifndef ARG_MAX

#define ARG_MAX 470

#endif

​

​

#ifdef TEST

# ifndef CONFIG_FEATURE_XARGS_SUPPORT_CONFIRMATION

#  define CONFIG_FEATURE_XARGS_SUPPORT_CONFIRMATION

# endif

# ifndef CONFIG_FEATURE_XARGS_SUPPORT_QUOTES

#  define CONFIG_FEATURE_XARGS_SUPPORT_QUOTES

# endif

# ifndef CONFIG_FEATURE_XARGS_SUPPORT_TERMOPT

#  define CONFIG_FEATURE_XARGS_SUPPORT_TERMOPT

# endif

# ifndef CONFIG_FEATURE_XARGS_SUPPORT_ZERO_TERM

#  define CONFIG_FEATURE_XARGS_SUPPORT_ZERO_TERM

# endif

#endif

​

/*

   This function has special algorithm.

   Don't use fork and include to main!

*/

static int xargs_exec(char *const *args)

{

    pid_t p;

    volatile int exec_errno = 0;    /* shared vfork stack */

    int status;

​

    p = vfork();

    if (p < 0)

        bb_perror_msg_and_die("vfork");

​

    if (p == 0) {

        /* vfork -- child */

        execvp(args[0], args);

        exec_errno = errno;     /* set error to shared stack */

        _exit(1);

    }

​

    /* vfork -- parent */

    while (wait(&status) == (pid_t) -1)

        if (errno != EINTR)

            break;

    if (exec_errno) {

        errno = exec_errno;

        bb_perror_msg("%s", args[0]);

        return exec_errno == ENOENT ? 127 : 126;

    }

    if (WEXITSTATUS(status) == 255) {

        bb_error_msg("%s: exited with status 255; aborting", args[0]);

        return 124;

    }

    if (WIFSTOPPED(status)) {

        bb_error_msg("%s: stopped by signal %d",

            args[0], WSTOPSIG(status));

        return 125;

    }

    if (WIFSIGNALED(status)) {

        bb_error_msg("%s: terminated by signal %d",

            args[0], WTERMSIG(status));

        return 125;

    }

    if (WEXITSTATUS(status))

        return 123;