Simplify tty(1)

Add a usage line and print "not a tty" for all error cases.
This commit is contained in:
sin 2013-10-07 15:50:41 +01:00
parent 4b30e39348
commit f54c7b4cac

32
tty.c
View File

@ -1,24 +1,26 @@
/* See LICENSE file for copyright and license details. */ /* See LICENSE file for copyright and license details. */
#include <errno.h> #include <unistd.h>
#include <stdio.h> #include <stdio.h>
#include <stdlib.h> #include <stdlib.h>
#include <unistd.h> #include "util.h"
static void
usage(void)
{
eprintf("usage: %s\n", argv0);
}
int int
main(void) main(int argc, char *argv[])
{ {
char *tty; char *tty;
if((tty = ttyname(STDIN_FILENO))) { ARGBEGIN {
puts(tty); default:
return 0; usage();
} } ARGEND;
else if(errno == ENOTTY) {
puts("not a tty"); tty = ttyname(STDIN_FILENO);
return 1; puts(tty ? tty : "not a tty");
} return tty ? 0 : 1;
else {
perror("ttyname");
return 2;
}
} }