minix/usr.bin/printenv/printenv.c

103 lines
2.9 KiB
C
Raw Normal View History

/* $NetBSD: printenv.c,v 1.12 2011/09/06 18:26:55 joerg Exp $ */
/*
* Copyright (c) 1987, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
#ifndef lint
__COPYRIGHT("@(#) Copyright (c) 1987, 1993\
The Regents of the University of California. All rights reserved.");
#endif /* not lint */
#ifndef lint
/*static char sccsid[] = "from: @(#)printenv.c 8.2 (Berkeley) 5/4/95";*/
__RCSID("$NetBSD: printenv.c,v 1.12 2011/09/06 18:26:55 joerg Exp $");
#endif /* not lint */
#include <sys/types.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <err.h>
__dead static void usage(void);
/*
* printenv
*
* Bill Joy, UCB
* February, 1979
*/
int
main(int argc, char *argv[])
{
extern char **environ;
char *cp, **ep;
size_t len;
int ch;
while ((ch = getopt(argc, argv, "")) != -1)
switch(ch) {
case '?':
default:
usage();
}
argc -= optind;
argv += optind;
if (argc == 0) {
for (ep = environ; *ep; ep++)
(void)printf("%s\n", *ep);
exit(0);
}
if (argc != 1)
usage();
if (strchr(*argv, '=') != NULL)
errx(1, "Invalid environment variable %s", *argv);
len = strlen(*argv);
for (ep = environ; *ep; ep++)
if (!memcmp(*ep, *argv, len)) {
cp = *ep + len;
if (!*cp || *cp == '=') {
(void)printf("%s\n", *cp ? cp + 1 : cp);
exit(0);
}
}
exit(1);
}
static void
usage(void)
{
(void)fprintf(stderr, "Usage: printenv [name]\n");
exit(1);
}