BSD 4_3_Tahoe release

[unix-history] / usr / src / ucb / printenv.c

/*
* Copyright (c) 1987 Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that the above copyright notice and this paragraph are
* duplicated in all such forms and that any documentation,
* advertising materials, and other materials related to such
* distribution and use acknowledge that the software was developed
* by the University of California, Berkeley.  The name of the
* University may not be used to endorse or promote products derived
* from this software without specific prior written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/

#ifndef lint
char copyright[] =
"@(#) Copyright (c) 1987 Regents of the University of California.\n\
All rights reserved.\n";
#endif /* not lint */

#ifndef lint
static char sccsid[] = "@(#)printenv.c  5.3 (Berkeley) 6/29/88";
#endif /* not lint */

/*
* printenv
*
* Bill Joy, UCB
* February, 1979
*/
main(argc, argv)
       int argc;
       char **argv;
{
       extern char **environ;
       register char *cp, **ep;
       register int len;

       if (argc < 2) {
               for (ep = environ; *ep; ep++)
                       puts(*ep);
               exit(0);
       }
       len = strlen(*++argv);
       for (ep = environ; *ep; ep++)
               if (!strncmp(*ep, *argv, len)) {
                       cp = *ep + len;
                       if (!*cp || *cp == '=') {
                               puts(*cp ? cp + 1 : cp);
                               exit(0);
                       }
               }
       exit(1);
}