2.11BSD/src/ucb/printenv.c

/*
 * Copyright (c) 1980 Regents of the University of California.
 * All rights reserved.  The Berkeley software License Agreement
 * specifies the terms and conditions for redistribution.
 */

#ifndef lint
char copyright[] =
"@(#) Copyright (c) 1980 Regents of the University of California.\n\
 All rights reserved.\n";
#endif not lint

#ifndef lint
static char sccsid[] = "@(#)printenv.c	5.1 (Berkeley) 5/31/85";
#endif not lint

/*
 * printenv
 *
 * Bill Joy, UCB
 * February, 1979
 */

extern	char **environ;

main(argc, argv)
	int argc;
	char *argv[];
{
	register char **ep;
	int found = 0;

	argc--, argv++;
	if (environ)
		for (ep = environ; *ep; ep++)
			if (argc == 0 || prefix(argv[0], *ep)) {
				register char *cp = *ep;

				found++;
				if (argc) {
					while (*cp && *cp != '=')
						cp++;
					if (*cp == '=')
						cp++;
				}
				printf("%s\n", cp);
			}
	exit (!found);
}

prefix(cp, dp)
	char *cp, *dp;
{

	while (*cp && *dp && *cp == *dp)
		cp++, dp++;
	if (*cp == 0)
		return (*dp == '=');
	return (0);
}