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
main(const int argc,char * argv[])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
dogmt(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
errensure(void)151 errensure(void)
152 {
153 if (retval == EXIT_SUCCESS)
154 retval = EXIT_FAILURE;
155 }
156
157 static void
usage(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
display(char const * format,time_t now)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
timeout(FILE * fp,char const * format,struct tm const * tmp)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