48 lines
1.1 KiB
C
48 lines
1.1 KiB
C
/* mesg - enable or disable communications. Author: John J. Ribera */
|
|
|
|
/*
|
|
* mesg - enable or disable communications.
|
|
*
|
|
* Usage: mesg [ y | n ]
|
|
*
|
|
* 'mesg n' will turn off group and world permissions of the
|
|
* user's terminal.
|
|
* 'mesg y' will enable group and world to write to the user's
|
|
* tty.
|
|
* mesg with no parameters will put the writeable status
|
|
* onto stdout.
|
|
*
|
|
* Author: John J. Ribera, Jr. 09/09/90
|
|
*/
|
|
#include <sys/types.h>
|
|
#include <sys/stat.h>
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <unistd.h>
|
|
|
|
_PROTOTYPE( int main, (int argc, char *argv []) );
|
|
|
|
int main(argc, argv)
|
|
int argc;
|
|
char *argv[];
|
|
{
|
|
struct stat statb;
|
|
char *tty_name;
|
|
|
|
if ((tty_name = ttyname(0)) == NULL) exit(2);
|
|
if (stat(tty_name, &statb) == -1) exit(2);
|
|
if (--argc) {
|
|
if (*argv[1] == 'n') statb.st_mode = 0600;
|
|
else if (*argv[1] == 'y') statb.st_mode = 0620;
|
|
else {
|
|
fprintf(stderr, "mesg: usage: mesg [n|y]\n");
|
|
exit(2);
|
|
}
|
|
if (chmod(tty_name, statb.st_mode) == -1) exit(2);
|
|
} else printf((statb.st_mode & 020) ? "is y\n" : "is n\n");
|
|
|
|
if (statb.st_mode & 020) exit(0);
|
|
|
|
exit(1);
|
|
}
|
|
|