4.3BSD - /usr/src/bin/who.c

   1: /*
   2:  * Copyright (c) 1980 Regents of the University of California.
   3:  * All rights reserved.  The Berkeley software License Agreement
   4:  * specifies the terms and conditions for redistribution.
   5:  */
   6: 
   7: #ifndef lint
   8: char copyright[] =
   9: "@(#) Copyright (c) 1980 Regents of the University of California.\n\
  10:  All rights reserved.\n";
  11: #endif not lint
  12: 
  13: #ifndef lint
  14: static char sccsid[] = "@(#)who.c	5.1 (Berkeley) 5/2/85";
  15: #endif not lint
  16: 
  17: /*
  18:  * who
  19:  */
  20: 
  21: #include <stdio.h>
  22: #include <utmp.h>
  23: #include <pwd.h>
  24: #include <ctype.h>
  25: 
  26: #define NMAX sizeof(utmp.ut_name)
  27: #define LMAX sizeof(utmp.ut_line)
  28: #define HMAX sizeof(utmp.ut_host)
  29: 
  30: struct  utmp utmp;
  31: struct  passwd *pw;
  32: struct  passwd *getpwuid();
  33: char    hostname[32];
  34: 
  35: char    *ttyname(), *rindex(), *ctime(), *strcpy();
  36: 
  37: main(argc, argv)
  38:     int argc;
  39:     char **argv;
  40: {
  41:     register char *tp, *s;
  42:     register FILE *fi;
  43:     extern char _sobuf[];
  44: 
  45:     setbuf(stdout, _sobuf);
  46:     s = "/etc/utmp";
  47:     if(argc == 2)
  48:         s = argv[1];
  49:     if (argc == 3) {
  50:         tp = ttyname(0);
  51:         if (tp)
  52:             tp = rindex(tp, '/') + 1;
  53:         else {  /* no tty - use best guess from passwd file */
  54:             pw = getpwuid(getuid());
  55:             strncpy(utmp.ut_name, pw ? pw->pw_name : "?", NMAX);
  56:             strcpy(utmp.ut_line, "tty??");
  57:             time(&utmp.ut_time);
  58:             putline();
  59:             exit(0);
  60:         }
  61:     }
  62:     if ((fi = fopen(s, "r")) == NULL) {
  63:         puts("who: cannot open utmp");
  64:         exit(1);
  65:     }
  66:     while (fread((char *)&utmp, sizeof(utmp), 1, fi) == 1) {
  67:         if (argc == 3) {
  68:             gethostname(hostname, sizeof (hostname));
  69:             if (strcmp(utmp.ut_line, tp))
  70:                 continue;
  71:             printf("%s!", hostname);
  72:             putline();
  73:             exit(0);
  74:         }
  75:         if (utmp.ut_name[0] == '\0' && argc == 1)
  76:             continue;
  77:         putline();
  78:     }
  79: }
  80: 
  81: putline()
  82: {
  83:     register char *cbuf;
  84: 
  85:     printf("%-*.*s %-*.*s",
  86:         NMAX, NMAX, utmp.ut_name,
  87:         LMAX, LMAX, utmp.ut_line);
  88:     cbuf = ctime(&utmp.ut_time);
  89:     printf("%.12s", cbuf+4);
  90:     if (utmp.ut_host[0])
  91:         printf("\t(%.*s)", HMAX, utmp.ut_host);
  92:     putchar('\n');
  93: }

Defined functions

Defined variables

Defined macros