1 /* 2 * Copyright (c) 1980, 1987 Regents of the University of California. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms are permitted 6 * provided that the above copyright notice and this paragraph are 7 * duplicated in all such forms and that any documentation, 8 * advertising materials, and other materials related to such 9 * distribution and use acknowledge that the software was developed 10 * by the University of California, Berkeley. The name of the 11 * University may not be used to endorse or promote products derived 12 * from this software without specific prior written permission. 13 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR 14 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED 15 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. 16 */ 17 18 #ifndef lint 19 char copyright[] = 20 "@(#) Copyright (c) 1980, 1987 Regents of the University of California.\n\ 21 All rights reserved.\n"; 22 #endif /* not lint */ 23 24 #ifndef lint 25 static char sccsid[] = "@(#)users.c 5.6 (Berkeley) 06/29/88"; 26 #endif /* not lint */ 27 28 /* 29 * users 30 */ 31 #include <sys/types.h> 32 #include <utmp.h> 33 #include <stdio.h> 34 35 #define NMAX sizeof(utmp.ut_name) 36 #define MAXUSERS 200 37 #define UTMP_FILE "/etc/utmp" 38 39 static struct utmp utmp; /* read structure */ 40 static int ncnt; /* count of names */ 41 static char *names[MAXUSERS]; /* names table */ 42 43 main() 44 { 45 register FILE *fp; /* file pointer */ 46 47 if (!(fp = fopen(UTMP_FILE, "r"))) { 48 perror(UTMP_FILE); 49 exit(1); 50 } 51 while (fread((char *)&utmp, sizeof(utmp), 1, fp) == 1) 52 if (*utmp.ut_name) { 53 if (++ncnt > MAXUSERS) { 54 ncnt = MAXUSERS; 55 fputs("users: too many users.\n", stderr); 56 break; 57 } 58 nsave(); 59 } 60 summary(); 61 exit(0); 62 } 63 64 nsave() 65 { 66 static char **namp = names; /* pointer to names table */ 67 char *calloc(); 68 69 if (!(*namp = calloc((u_int)(NMAX + 1), sizeof(char)))) { 70 fputs("users: malloc error.\n", stderr); 71 exit(1); 72 } 73 bcopy(utmp.ut_name, *namp++, NMAX); 74 } 75 76 summary() 77 { 78 register char **p; 79 int scmp(); 80 81 if (!ncnt) 82 return; 83 qsort((char *)names, ncnt, sizeof(names[0]), scmp); 84 fputs(names[0], stdout); 85 for (p = &names[1]; --ncnt; ++p) { 86 putchar(' '); 87 fputs(*p, stdout); 88 } 89 putchar('\n'); 90 } 91 92 scmp(p, q) 93 char **p, **q; 94 { 95 return(strcmp(*p, *q)); 96 } 97