1 .\" Copyright 2001 walter harms (walter.harms@informatik.uni-oldenburg.de)
2 .\" and Copyright 2008, Linux Foundation, written by Michael Kerrisk
3 .\" <mtk.manpages@gmail.com>
5 .\" %%%LICENSE_START(VERBATIM)
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11 .\" manual under the conditions for verbatim copying, provided that the
12 .\" entire resulting derived work is distributed under the terms of a
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15 .\" Since the Linux kernel and libraries are constantly changing, this
16 .\" manual page may be incorrect or out-of-date. The author(s) assume no
17 .\" responsibility for errors or omissions, or for damages resulting from
18 .\" the use of the information contained herein. The author(s) may not
19 .\" have taken the same level of care in the production of this manual,
20 .\" which is licensed free of charge, as they might when working
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27 .\" Modified, 2001-12-26, aeb
28 .\" 2008-09-07, mtk, Various rewrites; added an example program.
30 .TH GETDATE 3 2017-09-15 "" "Linux Programmer's Manual"
32 getdate, getdate_r \- convert a date-plus-time string to broken-down time
34 .B "#include <time.h>"
36 .BI "struct tm *getdate(const char *" string );
38 .B "extern int getdate_err;"
40 .B "#include <time.h>"
42 .BI "int getdate_r(const char *" string ", struct tm *" res );
45 Feature Test Macro Requirements for glibc (see
46 .BR feature_test_macros (7)):
52 _XOPEN_SOURCE\ >=\ 500
53 .\" || _XOPEN_SOURCE\ &&\ _XOPEN_SOURCE_EXTENDED
65 converts a string representation of a date and time,
66 contained in the buffer pointed to by
68 into a broken-down time.
69 The broken-down time is stored in a
71 structure, and a pointer to this
72 structure is returned as the function result.
75 structure is allocated in static storage,
76 and consequently it will be overwritten by further calls to
85 uses the formats found in the file
86 whose full pathname is given in the environment variable
88 The first line in the file that matches the given input string
89 is used for the conversion.
91 The matching is done case insensitively.
92 Superfluous whitespace, either in the pattern or in the string to
93 be converted, is ignored.
95 The conversion specifications that a pattern can contain are those given for
97 One more conversion specification is specified in POSIX.1-2001:
101 .\" FIXME Is it (still) true that %Z is not supported in glibc?
102 .\" Looking at the glibc 2.21 source code, where the implementation uses
103 .\" strptime(), suggests that it might be supported.
104 This is not implemented in glibc.
108 is given, the structure containing the broken-down time
109 is initialized with values corresponding to the current
110 time in the given timezone.
111 Otherwise, the structure is initialized to the broken-down time
112 corresponding to the current local time (as by a call to
115 When only the day of the week is given,
116 the day is taken to be the first such day
119 When only the month is given (and no year), the month is taken to
120 be the first such month equal to or after the current month.
121 If no day is given, it is the first day of the month.
123 When no hour, minute and second are given, the current
124 hour, minute and second are taken.
126 If no date is given, but we know the hour, then that hour is taken
127 to be the first such hour equal to or after the current hour.
130 is a GNU extension that provides a reentrant version of
132 Rather than using a global variable to report errors and a static buffer
133 to return the broken down time,
134 it returns errors via the function result value,
135 and returns the resulting broken-down time in the
136 caller-allocated buffer pointed to by the argument
141 returns a pointer to a
143 Otherwise, it returns NULL and sets the global variable
145 to one of the error numbers shown below.
153 on error it returns one of the error numbers shown below.
155 The following errors are returned via
159 or as the function result (for
165 environment variable is not defined, or its value is an empty string.
168 The template file specified by
170 cannot be opened for reading.
173 Failed to get file status information.
177 The template file is not a regular file.
180 An error was encountered while reading the template file.
183 Memory allocation failed (not enough memory available).
184 .\" Error 6 doesn't seem to occur in glibc
187 There is no line in the file that matches the input.
190 Invalid input specification.
194 File containing format patterns.
200 For an explanation of the terms used in this section, see
206 Interface Attribute Value
209 T} Thread safety MT-Unsafe race:getdate env locale
212 T} Thread safety MT-Safe env locale
215 POSIX.1-2001, POSIX.1-2008.
217 The POSIX.1 specification for
219 contains conversion specifications using the
223 modifier, while such specifications are not given for
229 so that precisely the same conversions are supported by both.
231 The program below calls
233 for each of its command-line arguments,
234 and for each call displays the values in the fields of the returned
237 The following shell session demonstrates the operation of the program:
241 .RB "$" " TFILE=$PWD/tfile"
242 .RB "$" " echo \(aq%A\(aq > $TFILE " " # Full name of the day of the week"
243 .RB "$" " echo \(aq%T\(aq >> $TFILE" " # ISO date (YYYY-MM-DD)"
244 .RB "$" " echo \(aq%F\(aq >> $TFILE" " # Time (HH:MM:SS)"
246 .RB "$" " export DATEMSK=$TFILE"
247 .RB "$" " ./a.out Tuesday \(aq2009-12-28\(aq \(aq12:22:33\(aq"
248 Sun Sep 7 06:03:36 CEST 2008
249 Call 1 ("Tuesday") succeeded:
259 Call 2 ("2009-12-28") succeeded:
269 Call 3 ("12:22:33") succeeded:
290 main(int argc, char *argv[])
295 for (j = 1; j < argc; j++) {
296 tmp = getdate(argv[j]);
299 printf("Call %d failed; getdate_err = %d\en",
304 printf("Call %d (\e"%s\e") succeeded:\en", j, argv[j]);
305 printf(" tm_sec = %d\en", tmp\->tm_sec);
306 printf(" tm_min = %d\en", tmp\->tm_min);
307 printf(" tm_hour = %d\en", tmp\->tm_hour);
308 printf(" tm_mday = %d\en", tmp\->tm_mday);
309 printf(" tm_mon = %d\en", tmp\->tm_mon);
310 printf(" tm_year = %d\en", tmp\->tm_year);
311 printf(" tm_wday = %d\en", tmp\->tm_wday);
312 printf(" tm_yday = %d\en", tmp\->tm_yday);
313 printf(" tm_isdst = %d\en", tmp\->tm_isdst);