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>
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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 2013-06-21 "" "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 This is not implemented in glibc.
105 is given, the structure containing the broken-down time
106 is initialized with values corresponding to the current
107 time in the given timezone.
108 Otherwise, the structure is initialized to the broken-down time
109 corresponding to the current local time (as by a call to
112 When only the weekday is given, the day is taken to be the first such day
115 When only the month is given (and no year), the month is taken to
116 be the first such month equal to or after the current month.
117 If no day is given, it is the first day of the month.
119 When no hour, minute and second are given, the current
120 hour, minute and second are taken.
122 If no date is given, but we know the hour, then that hour is taken
123 to be the first such hour equal to or after the current hour.
126 is a GNU extension that provides a reentrant version of
128 Rather than using a global variable to report errors and a static buffer
129 to return the broken down time,
130 it returns errors via the function result value,
131 and returns the resulting broken-down time in the
132 caller-allocated buffer pointed to by the argument
137 returns a pointer to a
139 Otherwise, it returns NULL and sets the global variable
141 to one of the error numbers shown below.
149 on error it returns one of the error numbers shown below.
151 The following errors are returned via
155 or as the function result (for
161 environment variable is not defined, or its value is an empty string.
164 The template file specified by
166 cannot be opened for reading.
169 Failed to get file status information.
173 The template file is not a regular file.
176 An error was encountered while reading the template file.
179 Memory allocation failed (not enough memory available).
180 .\" Error 6 doesn't seem to occur in glibc
183 There is no line in the file that matches the input.
186 Invalid input specification.
190 File containing format patterns.
196 .SS Multithreading (see pthreads(7))
199 function is not thread-safe.
203 function is thread-safe.
207 The POSIX.1-2001 specification for
209 contains conversion specifications using the
213 modifier, while such specifications are not given for
219 so that precisely the same conversions are supported by both.
221 The program below calls
223 for each of its command-line arguments,
224 and for each call displays the values in the fields of the returned
227 The following shell session demonstrates the operation of the program:
231 .RB "$" " TFILE=$PWD/tfile"
232 .RB "$" " echo \(aq%A\(aq > $TFILE " " # Full weekday name"
233 .RB "$" " echo \(aq%T\(aq >> $TFILE" " # ISO date (YYYY-MM-DD)"
234 .RB "$" " echo \(aq%F\(aq >> $TFILE" " # Time (HH:MM:SS)"
236 .RB "$" " export DATEMSK=$TFILE"
237 .RB "$" " ./a.out Tuesday \(aq2009-12-28\(aq \(aq12:22:33\(aq"
238 Sun Sep 7 06:03:36 CEST 2008
239 Call 1 ("Tuesday") succeeded:
249 Call 2 ("2009-12-28") succeeded:
259 Call 3 ("12:22:33") succeeded:
274 #define _GNU_SOURCE 500
280 main(int argc, char *argv[])
285 for (j = 1; j < argc; j++) {
286 tmp = getdate(argv[j]);
289 printf("Call %d failed; getdate_err = %d\\n",
294 printf("Call %d (\\"%s\\") succeeded:\\n", j, argv[j]);
295 printf(" tm_sec = %d\\n", tmp\->tm_sec);
296 printf(" tm_min = %d\\n", tmp\->tm_min);
297 printf(" tm_hour = %d\\n", tmp\->tm_hour);
298 printf(" tm_mday = %d\\n", tmp\->tm_mday);
299 printf(" tm_mon = %d\\n", tmp\->tm_mon);
300 printf(" tm_year = %d\\n", tmp\->tm_year);
301 printf(" tm_wday = %d\\n", tmp\->tm_wday);
302 printf(" tm_yday = %d\\n", tmp\->tm_yday);
303 printf(" tm_isdst = %d\\n", tmp\->tm_isdst);