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 .\" Permission is granted to make and distribute verbatim copies of this
6 .\" manual provided the copyright notice and this permission notice are
7 .\" preserved on all copies.
9 .\" Permission is granted to copy and distribute modified versions of this
10 .\" manual under the conditions for verbatim copying, provided that the
11 .\" entire resulting derived work is distributed under the terms of a
12 .\" permission notice identical to this one.
14 .\" Since the Linux kernel and libraries are constantly changing, this
15 .\" manual page may be incorrect or out-of-date. The author(s) assume no
16 .\" responsibility for errors or omissions, or for damages resulting from
17 .\" the use of the information contained herein. The author(s) may not
18 .\" have taken the same level of care in the production of this manual,
19 .\" which is licensed free of charge, as they might when working
22 .\" Formatted or processed versions of this manual, if unaccompanied by
23 .\" the source, must acknowledge the copyright and authors of this work.
25 .\" Modified, 2001-12-26, aeb
26 .\" 2008-09-07, mtk, Various rewrites; added an example program.
28 .TH GETDATE 3 2008-09-07 "" "Linux Programmer's Manual"
30 getdate, getdate_r \- convert a date-plus-time string to broken-down time
32 .B "#define _XOPEN_SOURCE 500"
34 .B "#include <time.h>"
36 .BI "struct tm *getdate(const char *" string );
38 .B "extern int getdate_err;"
40 .B "#define _GNU_SOURCE"
42 .B "#include <time.h>"
44 .BI "int getdate_r(const char *" string ", struct tm *" res );
48 converts a string representation of a date and time,
49 contained in the buffer pointed to by
51 into a broken-down time.
52 The broken-down time is stored in a
54 structure, and a pointer to this
55 structure is returned as the function result.
58 structure is allocated in static storage,
59 and consequently it will be overwritten by further calls to
68 uses the formats found in the file
69 whose full pathname is given in the environment variable
71 The first line in the file that matches the given input string
72 is used for the conversion.
74 The matching is done case insensitively.
75 Superfluous whitespace, either in the pattern or in the string to
76 be converted, is ignored.
78 The conversion specifications that a pattern can contain are those given for
80 One more conversion specification is specified in POSIX.1-2001:
84 This is not implemented in glibc.
88 is given, the structure containing the broken-down time
89 is initialized with values corresponding to the current
90 time in the given timezone.
91 Otherwise, the structure is initialized to the broken-down time
92 corresponding to the current local time (as by a call to
95 When only the weekday is given, the day is taken to be the first such day
98 When only the month is given (and no year), the month is taken to
99 be the first such month equal to or after the current month.
100 If no day is given, it is the first day of the month.
102 When no hour, minute and second are given, the current
103 hour, minute and second are taken.
105 If no date is given, but we know the hour, then that hour is taken
106 to be the first such hour equal to or after the current hour.
109 is a GNU extension that provides a reentrant version of
111 Rather than using a global variable to report errors and a static buffer
112 to return the broken down time,
113 it returns errors via the function result value,
114 and returns the resulting broken-down time in the
115 caller-allocated buffer pointed to by the argument
120 returns a pointer to a
122 Otherwise, it returns NULL and sets the global variable
124 to one of the error numbers shown below.
132 on error it returns one of the error numbers shown below.
134 The following errors are returned via
138 or as the function result (for
144 environment variable is not defined, or its value is an empty string.
147 The template file specified by
149 cannot be opened for reading.
152 Failed to get file status information.
156 The template file is not a regular file.
159 An error was encountered while reading the template file.
162 Memory allocation failed (not enough memory available).
163 .\" Error 6 doesn't seem to occur in glibc
166 There is no line in the file that matches the input.
169 Invalid input specification.
173 File containing format patterns.
181 The POSIX.1-2001 specification for
183 contains conversion specifications using the
187 modifier, while such specifications are not given for
193 so that precisely the same conversions are supported by both.
195 The program below calls
197 for each of its command-line arguments,
198 and for each call displays the values in the fields of the returned
201 The following shell session demonstrates the operation of the program:
205 .RB "$" " TFILE=$PWD/tfile"
206 .RB "$" " echo \(aq%A\(aq > $TFILE " " # Full weekday name"
207 .RB "$" " echo \(aq%T\(aq >> $TFILE" " # ISO date (YYYY-MM-DD)"
208 .RB "$" " echo \(aq%F\(aq >> $TFILE" " # Time (HH:MM:SS)"
210 .RB "$" " export DATEMSK=$TFILE"
211 .RB "$" " ./a.out Tuesday \(aq2009-12-28\(aq \(aq12:22:33\(aq"
212 Sun Sep 7 06:03:36 CEST 2008
213 Call 1 ("Tuesday") succeeded:
223 Call 2 ("2009-12-28") succeeded:
233 Call 3 ("12:22:33") succeeded:
248 #define _GNU_SOURCE 500
254 main(int argc, char *argv[])
259 for (j = 1; j < argc; j++) {
260 tmp = getdate(argv[j]);
263 printf("Call %d failed; getdate_err = %d\\n",
268 printf("Call %d (\\"%s\\") succeeded:\\n", j, argv[j]);
269 printf(" tm_sec = %d\\n", tmp\->tm_sec);
270 printf(" tm_min = %d\\n", tmp\->tm_min);
271 printf(" tm_hour = %d\\n", tmp\->tm_hour);
272 printf(" tm_mday = %d\\n", tmp\->tm_mday);
273 printf(" tm_mon = %d\\n", tmp\->tm_mon);
274 printf(" tm_year = %d\\n", tmp\->tm_year);
275 printf(" tm_wday = %d\\n", tmp\->tm_wday);
276 printf(" tm_yday = %d\\n", tmp\->tm_yday);
277 printf(" tm_isdst = %d\\n", tmp\->tm_isdst);
289 .BR feature_test_macros (7)