ack/lang/cem/libcc/gen/ttyslot.c
1987-01-27 15:57:55 +00:00

72 lines
1.2 KiB
C

#ifdef USG
/* some systems require inclusion of sys/types.h before utmp.h */
#include <sys/types.h>
#include <utmp.h>
/* system V, so no /etc/ttys file. In this case, scan the
/etc/utmp file
*/
#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)) {
if ((buf.ut_type == INIT_PROCESS ||
buf.ut_type == LOGIN_PROCESS ||
buf.ut_type == USER_PROCESS ||
buf.ut_type == DEAD_PROCESS) &&
! 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
}