LXR busybox/coreutils/env.c

   1/* vi: set sw=4 ts=4: */
   2/*
   3 * env implementation for busybox
   4 *
   5 * Copyright (c) 1988, 1993, 1994
   6 * The Regents of the University of California.  All rights reserved.
   7 *
   8 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
   9 *
  10 * Original copyright notice is retained at the end of this file.
  11 *
  12 * Modified for BusyBox by Erik Andersen <andersen@codepoet.org>
  13 */
  14/* Mar 16, 2003      Manuel Novoa III   (mjn3@codepoet.org)
  15 *
  16 * Fixed bug involving exit return codes if execvp fails.  Also added
  17 * output error checking.
  18 */
  19/*
  20 * Modified by Vladimir Oleynik <dzo@simtreas.ru> (C) 2003
  21 * - correct "-" option usage
  22 * - multiple "-u unsetenv" support
  23 * - GNU long option support
  24 * - use xfunc_error_retval
  25 */
  26//config:config ENV
  27//config:       bool "env (4 kb)"
  28//config:       default y
  29//config:       help
  30//config:       env is used to set an environment variable and run
  31//config:       a command; without options it displays the current
  32//config:       environment.
  33
  34//applet:IF_ENV(APPLET_NOEXEC(env, env, BB_DIR_USR_BIN, BB_SUID_DROP, env))
  35
  36//kbuild:lib-$(CONFIG_ENV) += env.o
  37
  38/* BB_AUDIT SUSv3 compliant */
  39/* http://www.opengroup.org/onlinepubs/007904975/utilities/env.html */
  40
  41//usage:#define env_trivial_usage
  42//usage:       "[-i0] [-u NAME]... [-] [NAME=VALUE]... [PROG ARGS]"
  43// The "-" can occur only once (unlike, say, -i): it terminates option processing,
  44// so if it is followed by another "-" arg (or any option-looking arg),
  45// that arg will be taken as PROG (or even as NAME=VALUE, example: "-z=QWE").
  46//usage:#define env_full_usage "\n\n"
  47//usage:       "Print current environment or run PROG after setting up environment\n"
  48//usage:     "\n        -, -i   Start with empty environment"
  49//usage:     "\n        -0      NUL terminated output"
  50//usage:     "\n        -u NAME Remove variable from environment"
  51
  52#include "libbb.h"
  53
  54int env_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  55int env_main(int argc UNUSED_PARAM, char **argv)
  56{
  57        unsigned opts;
  58        llist_t *unset_env = NULL;
  59
  60        opts = getopt32long(argv, "+i0u:*",
  61                        "ignore-environment\0" No_argument       "i"
  62                        "null\0"               No_argument       "0"
  63                        "unset\0"              Required_argument "u"
  64                        , &unset_env
  65        );
  66        argv += optind;
  67        if (argv[0] && LONE_DASH(argv[0])) {
  68                opts |= 1;
  69                ++argv;
  70        }
  71        if (opts & 1) {
  72                clearenv();
  73        }
  74        while (unset_env) {
  75                char *var = llist_pop(&unset_env);
  76                /* This does not handle -uVAR=VAL
  77                 * (coreutils _sets_ the variable in that case): */
  78                /*unsetenv(var);*/
  79                /* This does, but uses somewhan undocumented feature that
  80                 * putenv("name_without_equal_sign") unsets the variable: */
  81                putenv(var);
  82        }
  83
  84        while (*argv && (strchr(*argv, '=') != NULL)) {
  85                if (putenv(*argv) < 0) {
  86                        bb_simple_perror_msg_and_die("putenv");
  87                }
  88                ++argv;
  89        }
  90
  91        if (argv[0]) {
  92                BB_EXECVP_or_die(argv);
  93        }
  94
  95        if (environ) { /* clearenv() may set environ == NULL! */
  96                char **ep;
  97                opts = (opts & 2) ? 0 : '\n';
  98                for (ep = environ; *ep; ep++) {
  99                        printf("%s%c", *ep, opts);
 100                }
 101        }
 102
 103        fflush_stdout_and_exit(EXIT_SUCCESS);
 104}
 105
 106/*
 107 * Copyright (c) 1988, 1993, 1994
 108 *      The Regents of the University of California.  All rights reserved.
 109 *
 110 * Redistribution and use in source and binary forms, with or without
 111 * modification, are permitted provided that the following conditions
 112 * are met:
 113 * 1. Redistributions of source code must retain the above copyright
 114 *    notice, this list of conditions and the following disclaimer.
 115 * 2. Redistributions in binary form must reproduce the above copyright
 116 *    notice, this list of conditions and the following disclaimer in the
 117 *    documentation and/or other materials provided with the distribution.
 118 *
 119 * 3. BSD Advertising Clause omitted per the July 22, 1999 licensing change
 120 *    ftp://ftp.cs.berkeley.edu/pub/4bsd/README.Impt.License.Change
 121 *
 122 * 4. Neither the name of the University nor the names of its contributors
 123 *    may be used to endorse or promote products derived from this software
 124 *    without specific prior written permission.
 125 *
 126 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ''AS IS'' AND
 127 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 128 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 129 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 130 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 131 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 132 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 133 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 134 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 135 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 136 * SUCH DAMAGE.
 137 */
 138