/* * who */ #include #include #include struct utmp utmp; struct passwd *pw; struct passwd *getpwuid(); char *ttyname(), *rindex(), *ctime(), *strcpy(), *index(); main(argc, argv) char **argv; { register char *tp, *s; register FILE *fi; s = "/etc/utmp"; if(argc == 2) s = argv[1]; if (argc==3) { tp = ttyname(0); if (tp) tp = index(tp+1, '/') + 1; else { /* no tty - use best guess from passwd file */ pw = getpwuid(getuid()); strcpy(utmp.ut_name, pw?pw->pw_name: "?"); strcpy(utmp.ut_line, "tty??"); time(&utmp.ut_time); putline(); exit(0); } } if ((fi = fopen(s, "r")) == NULL) { puts("who: cannot open utmp"); exit(1); } while (fread((char *)&utmp, sizeof(utmp), 1, fi) == 1) { if(argc==3) { if (strcmp(utmp.ut_line, tp)) continue; #ifdef interdata printf("(Interdata) "); #endif putline(); exit(0); } if(utmp.ut_name[0] == '\0' && argc==1) continue; putline(); } } putline() { register char *cbuf; printf("%-8.8s %-8.8s", utmp.ut_name, utmp.ut_line); cbuf = ctime(&utmp.ut_time); printf("%.12s\n", cbuf+4); }