last.c (1099B)
1 /* See LICENSE file for copyright and license details. */ 2 #include <errno.h> 3 #include <libgen.h> 4 #include <paths.h> 5 #include <pwd.h> 6 #include <stdio.h> 7 #include <stdlib.h> 8 #include <string.h> 9 #include <time.h> 10 #include <utmp.h> 11 #include <unistd.h> 12 13 #include "config.h" 14 #include "util.h" 15 16 static void 17 usage(void) 18 { 19 eprintf("usage: %s [user]\n", argv0); 20 } 21 22 int 23 main(int argc, char **argv) 24 { 25 FILE *fp; 26 struct utmp ut; 27 char *user, *file, *prog; 28 time_t t; 29 30 ARGBEGIN { 31 default: 32 usage(); 33 } ARGEND; 34 35 switch (argc) { 36 case 0: 37 user = NULL; 38 break; 39 case 1: 40 user = argv[0]; 41 break; 42 default: 43 usage(); 44 } 45 46 prog = basename(argv0); 47 file = (!strcmp(prog, "last")) ? WTMP_PATH : BTMP_PATH; 48 if ((fp = fopen(file, "r")) == NULL) 49 eprintf("fopen %s:", file); 50 51 while (fread(&ut, sizeof(ut), 1, fp) == 1) { 52 if (ut.ut_type != USER_PROCESS || 53 (user && strcmp(user, ut.ut_name))) { 54 continue; 55 } 56 57 t = ut.ut_time; 58 printf("%-8.8s %-8.8s %-16.16s %s", 59 ut.ut_user, ut.ut_line, ut.ut_host, ctime(&t)); 60 } 61 if (fclose(fp)) 62 eprintf("fclose %s:", file); 63 return 0; 64 }