- s = "/etc/utmp";
- if(argc == 2)
- s = argv[1];
- if (argc == 3) {
- tp = ttyname(0);
- if (tp)
- tp = rindex(tp, '/') + 1;
- else { /* no tty - use best guess from passwd file */
- strcpy(utmp.ut_line, "tty??");
- guess();
- exit(0);
- }
- }
- if ((fi = fopen(s, "r")) == NULL) {
- puts("who: cannot open utmp");
+ switch (argc) {
+ case 1: /* who */
+ ufp = file(_PATH_UTMP);
+ /* only entries with both name and line fields */
+ while (fread((char *)&usr, sizeof(usr), 1, ufp) == 1)
+ if (*usr.ut_name && *usr.ut_line)
+ output(&usr);
+ break;
+ case 2: /* who utmp_file */
+ ufp = file(argv[1]);
+ /* all entries */
+ while (fread((char *)&usr, sizeof(usr), 1, ufp) == 1)
+ output(&usr);
+ break;
+ case 3: /* who am i */
+ ufp = file(_PATH_UTMP);
+
+ /* search through the utmp and find an entry for this tty */
+ if (p = ttyname(0)) {
+ /* strip any directory component */
+ if (t = rindex(p, '/'))
+ p = t + 1;
+ while (fread((char *)&usr, sizeof(usr), 1, ufp) == 1)
+ if (usr.ut_name && !strcmp(usr.ut_line, p)) {
+ output(&usr);
+ exit(0);
+ }
+ /* well, at least we know what the tty is */
+ (void)strncpy(usr.ut_line, p, UT_LINESIZE);
+ } else
+ (void)strcpy(usr.ut_line, "tty??");
+ pw = getpwuid(getuid());
+ (void)strncpy(usr.ut_name, pw ? pw->pw_name : "?", UT_NAMESIZE);
+ (void)time(&usr.ut_time);
+ *usr.ut_host = '\0';
+ output(&usr);
+ break;
+ default:
+ (void)fprintf(stderr, "usage: who [ file ]\n who am i\n");