minix/commands/env/env.c
2010-05-12 16:28:54 +00:00

83 lines
1.7 KiB
C

/* env 1.1 - Set environment for command Author: Kees J. Bot
* 17 Dec 1997
*/
#define nil 0
#include <sys/types.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
int main(int argc, char **argv)
{
int i;
int iflag= 0;
int aflag= 0;
extern char **environ;
i= 1;
while (i < argc && argv[i][0] == '-') {
char *opt= argv[i++] + 1;
if (opt[0] == '-' && opt[1] == 0) break; /* -- */
if (opt[0] == 0) iflag= 1; /* - */
while (*opt != 0) switch (*opt++) {
case 'i':
iflag= 1; /* Clear environment. */
break;
case 'a': /* Specify arg 0 separately. */
aflag= 1;
break;
default:
fprintf(stderr,
"Usage: env [-ia] [name=value] ... [utility [argument ...]]\n");
exit(1);
}
}
/* Clear the environment if -i. */
if (iflag) *environ= nil;
/* Set the new environment strings. */
while (i < argc && strchr(argv[i], '=') != nil) {
if (putenv(argv[i]) != 0) {
fprintf(stderr, "env: Setting '%s' failed: %s\n",
argv[i], strerror(errno));
exit(1);
}
i++;
}
/* Environment settings and command may be separated with '--'.
* This is for compatibility with other envs, we don't advertise it.
*/
if (i < argc && strcmp(argv[i], "--") == 0) i++;
if (i >= argc) {
/* No utility given; print environment. */
char **ep;
for (ep= environ; *ep != nil; ep++) {
if (puts(*ep) == EOF) {
fprintf(stderr, "env: %s\n", strerror(errno));
exit(1);
}
}
return 0;
} else {
char *util, **args;
int err;
util= argv[i];
args= argv + i;
if (aflag) args++;
(void) execvp(util, args);
err= errno;
fprintf(stderr, "env: Can't execute %s: %s\n",
util, strerror(err));
return err == ENOENT ? 127 : 126;
}
}