1 /* Display or set the current time and date. */ 2 3 /* Copyright 1985, 1987, 1988 The Regents of the University of California. 4 All rights reserved. 5 6 Redistribution and use in source and binary forms, with or without 7 modification, are permitted provided that the following conditions 8 are met: 9 1. Redistributions of source code must retain the above copyright 10 notice, this list of conditions and the following disclaimer. 11 2. Redistributions in binary form must reproduce the above copyright 12 notice, this list of conditions and the following disclaimer in the 13 documentation and/or other materials provided with the distribution. 14 3. Neither the name of the University nor the names of its contributors 15 may be used to endorse or promote products derived from this software 16 without specific prior written permission. 17 18 THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS "AS IS" AND 19 ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22 FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 SUCH DAMAGE. */ 29 30 #include "private.h" 31 #include <locale.h> 32 #include <stdio.h> 33 34 #if !HAVE_POSIX_DECLS 35 extern char * optarg; 36 extern int optind; 37 #endif 38 39 static int retval = EXIT_SUCCESS; 40 41 static void display(const char *, time_t); 42 static void dogmt(void); 43 static void errensure(void); 44 static void timeout(FILE *, const char *, const struct tm *); 45 ATTRIBUTE_NORETURN static void usage(void); 46 47 int 48 main(const int argc, char *argv[]) 49 { 50 register const char * format = "+%+"; 51 register int ch; 52 register bool rflag = false; 53 time_t t; 54 intmax_t secs; 55 char * endarg; 56 57 #ifdef LC_ALL 58 setlocale(LC_ALL, ""); 59 #endif /* defined(LC_ALL) */ 60 #if HAVE_GETTEXT 61 # ifdef TZ_DOMAINDIR 62 bindtextdomain(TZ_DOMAIN, TZ_DOMAINDIR); 63 # endif /* defined(TEXTDOMAINDIR) */ 64 textdomain(TZ_DOMAIN); 65 #endif /* HAVE_GETTEXT */ 66 t = time(NULL); 67 while ((ch = getopt(argc, argv, "ucr:")) != EOF && ch != -1) { 68 switch (ch) { 69 default: 70 usage(); 71 case 'u': /* do it in UT */ 72 case 'c': 73 dogmt(); 74 break; 75 case 'r': /* seconds since 1970 */ 76 if (rflag) { 77 fprintf(stderr, 78 _("date: error: multiple -r's used")); 79 usage(); 80 } 81 rflag = true; 82 errno = 0; 83 secs = strtoimax(optarg, &endarg, 0); 84 if (*endarg || optarg == endarg) 85 errno = EINVAL; 86 else if (! (TIME_T_MIN <= secs && secs <= TIME_T_MAX)) 87 errno = ERANGE; 88 if (errno) { 89 char const *e = strerror(errno); 90 fprintf(stderr, _("date: %s: %s\n"), 91 optarg, e); 92 errensure(); 93 exit(retval); 94 } 95 t = secs; 96 break; 97 } 98 } 99 if (optind < argc) { 100 if (argc - optind != 1) { 101 fprintf(stderr, 102 _("date: error: multiple operands in command line\n")); 103 usage(); 104 } 105 format = argv[optind]; 106 if (*format != '+') { 107 fprintf(stderr, _("date: unknown operand: %s\n"), format); 108 usage(); 109 } 110 } 111 112 display(format, t); 113 return retval; 114 } 115 116 static void 117 dogmt(void) 118 { 119 static char ** fakeenv; 120 121 if (fakeenv == NULL) { 122 static char tzeutc0[] = "TZ=UTC0"; 123 ptrdiff_t from, to, n; 124 125 for (n = 0; environ[n] != NULL; ++n) 126 continue; 127 #if defined ckd_add && defined ckd_mul 128 if (!ckd_add(&n, n, 2) && !ckd_mul(&n, n, sizeof *fakeenv) 129 && n <= INDEX_MAX) 130 fakeenv = malloc(n); 131 #else 132 if (n <= INDEX_MAX / sizeof *fakeenv - 2) 133 fakeenv = malloc((n + 2) * sizeof *fakeenv); 134 #endif 135 if (fakeenv == NULL) { 136 fprintf(stderr, _("date: Memory exhausted\n")); 137 errensure(); 138 exit(retval); 139 } 140 to = 0; 141 fakeenv[to++] = tzeutc0; 142 for (from = 1; environ[from] != NULL; ++from) 143 if (strncmp(environ[from], "TZ=", 3) != 0) 144 fakeenv[to++] = environ[from]; 145 fakeenv[to] = NULL; 146 environ = fakeenv; 147 } 148 } 149 150 static void 151 errensure(void) 152 { 153 if (retval == EXIT_SUCCESS) 154 retval = EXIT_FAILURE; 155 } 156 157 static void 158 usage(void) 159 { 160 fprintf(stderr, 161 _("date: usage: date [-u] [-c] [-r seconds]" 162 " [+format]\n")); 163 errensure(); 164 exit(retval); 165 } 166 167 static void 168 display(char const *format, time_t now) 169 { 170 struct tm *tmp; 171 172 tmp = localtime(&now); 173 if (!tmp) { 174 fprintf(stderr, 175 _("date: error: time out of range\n")); 176 errensure(); 177 return; 178 } 179 timeout(stdout, format, tmp); 180 putchar('\n'); 181 fflush(stdout); 182 fflush(stderr); 183 if (ferror(stdout) || ferror(stderr)) { 184 fprintf(stderr, 185 _("date: error: couldn't write results\n")); 186 errensure(); 187 } 188 } 189 190 static void 191 timeout(FILE *fp, char const *format, struct tm const *tmp) 192 { 193 char *cp = NULL; 194 ptrdiff_t result; 195 ptrdiff_t size = 1024 / 2; 196 197 for ( ; ; ) { 198 #ifdef ckd_mul 199 bool bigger = !ckd_mul(&size, size, 2) && size <= INDEX_MAX; 200 #else 201 bool bigger = size <= INDEX_MAX / 2 && (size *= 2, true); 202 #endif 203 char *newcp = bigger ? realloc(cp, size) : NULL; 204 if (!newcp) { 205 fprintf(stderr, 206 _("date: error: can't get memory\n")); 207 errensure(); 208 exit(retval); 209 } 210 cp = newcp; 211 result = strftime(cp, size, format, tmp); 212 if (result != 0) 213 break; 214 } 215 fwrite(cp + 1, 1, result - 1, fp); 216 free(cp); 217 } 218