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 static int retval = EXIT_SUCCESS;
35
36 static void display(const char *, time_t);
37 static void dogmt(void);
38 static void errensure(void);
39 static void timeout(FILE *, const char *, const struct tm *);
40 ATTRIBUTE_NORETURN static void usage(void);
41
42 int
main(const int argc,char * argv[])43 main(const int argc, char *argv[])
44 {
45 register const char * format = "+%+";
46 register int ch;
47 register bool rflag = false;
48 time_t t;
49 intmax_t secs;
50 char * endarg;
51
52 #ifdef LC_ALL
53 setlocale(LC_ALL, "");
54 #endif /* defined(LC_ALL) */
55 #if HAVE_GETTEXT
56 # ifdef TZ_DOMAINDIR
57 bindtextdomain(TZ_DOMAIN, TZ_DOMAINDIR);
58 # endif /* defined(TEXTDOMAINDIR) */
59 textdomain(TZ_DOMAIN);
60 #endif /* HAVE_GETTEXT */
61 t = time(NULL);
62 while ((ch = getopt(argc, argv, "ucr:")) != -1) {
63 switch (ch) {
64 default:
65 usage();
66 case 'u': /* do it in UT */
67 case 'c':
68 dogmt();
69 break;
70 case 'r': /* seconds since 1970 */
71 if (rflag) {
72 fprintf(stderr,
73 _("date: error: multiple -r's used"));
74 usage();
75 }
76 rflag = true;
77 errno = 0;
78 secs = strtoimax(optarg, &endarg, 0);
79 if (*endarg || optarg == endarg)
80 errno = EINVAL;
81 else if (! (TIME_T_MIN <= secs && secs <= TIME_T_MAX))
82 errno = ERANGE;
83 if (errno) {
84 char const *e = strerror(errno);
85 fprintf(stderr, _("date: %s: %s\n"),
86 optarg, e);
87 errensure();
88 exit(retval);
89 }
90 t = secs;
91 break;
92 }
93 }
94 if (optind < argc) {
95 if (argc - optind != 1) {
96 fprintf(stderr,
97 _("date: error: multiple operands in command line\n"));
98 usage();
99 }
100 format = argv[optind];
101 if (*format != '+') {
102 fprintf(stderr, _("date: unknown operand: %s\n"), format);
103 usage();
104 }
105 }
106
107 display(format, t);
108 return retval;
109 }
110
111 static void
dogmt(void)112 dogmt(void)
113 {
114 static char ** fakeenv;
115
116 if (fakeenv == NULL) {
117 static char tzeutc0[] = "TZ=UTC0";
118 ptrdiff_t from, to, n;
119
120 for (n = 0; environ[n] != NULL; ++n)
121 continue;
122 #if defined ckd_add && defined ckd_mul
123 if (!ckd_add(&n, n, 2) && !ckd_mul(&n, n, sizeof *fakeenv)
124 && n <= INDEX_MAX)
125 fakeenv = malloc(n);
126 #else
127 if (n <= INDEX_MAX / sizeof *fakeenv - 2)
128 fakeenv = malloc((n + 2) * sizeof *fakeenv);
129 #endif
130 if (fakeenv == NULL) {
131 fprintf(stderr, _("date: Memory exhausted\n"));
132 errensure();
133 exit(retval);
134 }
135 to = 0;
136 fakeenv[to++] = tzeutc0;
137 for (from = 1; environ[from] != NULL; ++from)
138 if (strncmp(environ[from], "TZ=", 3) != 0)
139 fakeenv[to++] = environ[from];
140 fakeenv[to] = NULL;
141 environ = fakeenv;
142 }
143 }
144
145 static void
errensure(void)146 errensure(void)
147 {
148 if (retval == EXIT_SUCCESS)
149 retval = EXIT_FAILURE;
150 }
151
152 static void
usage(void)153 usage(void)
154 {
155 fprintf(stderr,
156 _("date: usage: date [-u] [-c] [-r seconds]"
157 " [+format]\n"));
158 errensure();
159 exit(retval);
160 }
161
162 static void
display(char const * format,time_t now)163 display(char const *format, time_t now)
164 {
165 struct tm *tmp;
166
167 tmp = localtime(&now);
168 if (!tmp) {
169 fprintf(stderr,
170 _("date: error: time out of range\n"));
171 errensure();
172 return;
173 }
174 timeout(stdout, format, tmp);
175 putchar('\n');
176 fflush(stdout);
177 fflush(stderr);
178 if (ferror(stdout) || ferror(stderr)) {
179 fprintf(stderr,
180 _("date: error: couldn't write results\n"));
181 errensure();
182 }
183 }
184
185 static void
timeout(FILE * fp,char const * format,struct tm const * tmp)186 timeout(FILE *fp, char const *format, struct tm const *tmp)
187 {
188 char *cp = NULL;
189 ptrdiff_t result;
190 ptrdiff_t size = 1024 / 2;
191
192 for ( ; ; ) {
193 #ifdef ckd_mul
194 bool bigger = !ckd_mul(&size, size, 2) && size <= INDEX_MAX;
195 #else
196 bool bigger = size <= INDEX_MAX / 2 && (size *= 2, true);
197 #endif
198 char *newcp = bigger ? realloc(cp, size) : NULL;
199 if (!newcp) {
200 fprintf(stderr,
201 _("date: error: can't get memory\n"));
202 errensure();
203 exit(retval);
204 }
205 cp = newcp;
206 result = strftime(cp, size, format, tmp);
207 if (result != 0)
208 break;
209 }
210 fwrite(cp + 1, 1, result - 1, fp);
211 free(cp);
212 }
213