ack/lang/cem/libcc/gen/ttyslot.c

82 lines
1.4 KiB
C

#ifdef __USG
/* system V, so no /etc/ttys file. In this case, scan the
/etc/utmp file
*/
struct utmp {
char ut_name[8];
char ut_id[4];
char ut_line[12];
short ut_pid;
short ut_type;
struct exit_status {
short e_termination;
short e_exit;
} ut_exit;
long ut_time;
};
#define FILENAME "/etc/utmp"
#else
#define FILENAME "/etc/ttys"
#endif
char *ttyname();
char *rindex();
ttyslot()
{
register char *tp, *p;
int fd;
int retval = 1;
#ifdef __USG
struct utmp buf;
#else
char buf[32];
#endif
if (! (tp=ttyname(0)) && ! (tp=ttyname(1)) && !(tp=ttyname(2)))
return 0;
if (! (p = rindex(tp, '/')))
p = tp;
else
p++;
if ((fd = open(FILENAME, 0)) < 0) return 0;
#ifdef __USG
while (read(fd, (char *) &buf, sizeof(buf)) == sizeof(buf)) {
/* processes associated with a terminal ...
unfortunately we cannot use the include file because
some systems have a different one ...
INIT_PROCESS, DEAD_PROCESS, USER_PROCESS, LOGIN_PROCESS
*/
if ((buf.ut_type >= 5 && buf.ut_type <= 8) &&
! strncmp(buf.ut_line, p, sizeof(buf.ut_line))) {
close(fd);
return retval;
}
retval++;
}
close(fd);
return 0;
#else
for (;;) {
tp = buf;
for (;;) {
if (read(fd, tp, 1) != 1) {
close(fd);
return 0;
}
if (*tp == '\n' || tp >= &buf[31]) {
*tp = 0;
tp = buf+2;
break;
}
}
if (! strcmp(p, tp)) {
close(fd);
return retval;
}
retval++;
}
/*NOTREACHED*/
#endif
}