1 .\" Copyright 1993 Mitchum DSouza <m.dsouza@mrc-apu.cam.ac.uk>
3 .\" %%%LICENSE_START(VERBATIM)
4 .\" Permission is granted to make and distribute verbatim copies of this
5 .\" manual provided the copyright notice and this permission notice are
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8 .\" Permission is granted to copy and distribute modified versions of this
9 .\" manual under the conditions for verbatim copying, provided that the
10 .\" entire resulting derived work is distributed under the terms of a
11 .\" permission notice identical to this one.
13 .\" Since the Linux kernel and libraries are constantly changing, this
14 .\" manual page may be incorrect or out-of-date. The author(s) assume no
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18 .\" which is licensed free of charge, as they might when working
21 .\" Formatted or processed versions of this manual, if unaccompanied by
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25 .\" Modified, jmv@lucifer.dorms.spbu.ru, 1999-11-08
26 .\" Modified, aeb, 2000-04-07
27 .\" Updated from glibc docs, C. Scott Ananian, 2001-08-25
28 .\" Modified, aeb, 2001-08-31
29 .\" Modified, wharms 2001-11-12, remark on white space and example
31 .TH STRPTIME 3 2017-09-15 "GNU" "Linux Programmer's Manual"
33 strptime \- convert a string representation of time to a time tm structure
35 .BR "#define _XOPEN_SOURCE" " /* See feature_test_macros(7) */"
39 .BI "char *strptime(const char *" s ", const char *" format ,
40 .BI "struct tm *" tm );
44 function is the converse of
46 it converts the character string pointed to by
48 to values which are stored in the
50 structure pointed to by
52 using the format specified by
55 The broken-down time structure
64 int tm_sec; /* Seconds (0\-60) */
65 int tm_min; /* Minutes (0\-59) */
66 int tm_hour; /* Hours (0\-23) */
67 int tm_mday; /* Day of the month (1\-31) */
68 int tm_mon; /* Month (0\-11) */
69 int tm_year; /* Year \- 1900 */
70 int tm_wday; /* Day of the week (0\-6, Sunday = 0) */
71 int tm_yday; /* Day in the year (0\-365, 1 Jan = 0) */
72 int tm_isdst; /* Daylight saving time */
77 For more details on the
85 is a character string that consists of field descriptors and text characters,
88 Each field descriptor consists of a
90 character followed by another character that specifies the replacement
91 for the field descriptor.
92 All other characters in the
94 string must have a matching character in the input string,
95 except for whitespace, which matches zero or more
96 whitespace characters in the input string.
97 There should be white\%space or other alphanumeric characters
98 between any two field descriptors.
102 function processes the input string from left
104 Each of the three possible input elements (whitespace,
105 literal, or format) are handled one after the other.
106 If the input cannot be matched to the format string, the function stops.
107 The remainder of the format and input strings are not processed.
109 The supported input field descriptors are listed below.
110 In case a text string (such as the name of a day of the week or a month name)
111 is to be matched, the comparison is case insensitive.
112 In case a number is to be matched, leading zeros are
113 permitted but not required.
121 The name of the day of the week according to the current locale,
122 in abbreviated form or the full name.
124 .BR %b " or " %B " or " %h
125 The month name according to the current locale,
126 in abbreviated form or the full name.
129 The date and time representation for the current locale.
132 The century number (0\(en99).
135 The day of month (1\(en31).
140 (This is the American style date, very confusing
141 to non-Americans, especially since
143 is widely used in Europe.
144 The ISO 8601 standard format is
151 The hour on a 12-hour clock (1\(en12).
154 The day number in the year (1\(en366).
157 The month number (1\(en12).
160 The minute (0\(en59).
163 Arbitrary whitespace.
166 The locale's equivalent of AM or PM.
167 (Note: there may be none.)
170 The 12-hour clock time (using the locale's AM or PM).
171 In the POSIX locale equivalent to
177 part of the current locale,
178 then the behavior is undefined.
185 The second (0\(en60; 60 may occur for leap seconds;
186 earlier also 61 was allowed).
189 Arbitrary whitespace.
196 The week number with Sunday the first day of the week (0\(en53).
197 The first Sunday of January is the first day of week 1.
200 The ordinal number of the day of the week (0\(en6), with Sunday = 0.
203 The week number with Monday the first day of the week (0\(en53).
204 The first Monday of January is the first day of week 1.
207 The date, using the locale's date format.
210 The time, using the locale's time format.
213 The year within century (0\(en99).
214 When a century is not otherwise specified, values in the range 69\(en99 refer
215 to years in the twentieth century (1969\(en1999); values in the
216 range 00\(en68 refer to years in the twenty-first century (2000\(en2068).
219 The year, including century (for example, 1991).
221 Some field descriptors can be modified by the E or O modifier characters
222 to indicate that an alternative format or specification should be used.
224 alternative format or specification does not exist in the current locale, the
225 unmodified field descriptor is used.
227 The E modifier specifies that the input string may contain
228 alternative locale-dependent versions of the date and time representation:
231 The locale's alternative date and time representation.
234 The name of the base year (period) in the locale's alternative representation.
237 The locale's alternative date representation.
240 The locale's alternative time representation.
245 (year only) in the locale's alternative representation.
248 The full alternative year representation.
250 The O modifier specifies that the numerical input may be in an
251 alternative locale-dependent format:
254 The day of the month using the locale's alternative numeric symbols;
255 leading zeros are permitted but not required.
258 The hour (24-hour clock) using the locale's alternative numeric symbols.
261 The hour (12-hour clock) using the locale's alternative numeric symbols.
264 The month using the locale's alternative numeric symbols.
267 The minutes using the locale's alternative numeric symbols.
270 The seconds using the locale's alternative numeric symbols.
273 The week number of the year (Sunday as the first day of the week)
274 using the locale's alternative numeric symbols.
277 The ordinal number of the day of the week (Sunday=0),
278 using the locale's alternative numeric symbols.
281 The week number of the year (Monday as the first day of the week)
282 using the locale's alternative numeric symbols.
285 The year (offset from
287 using the locale's alternative numeric symbols.
289 The return value of the function is a pointer to the first character
290 not processed in this function call.
291 In case the input string
292 contains more characters than required by the format string, the return
293 value points right after the last consumed input character.
294 In case the whole input string is consumed,
295 the return value points to the null byte at the end of the string.
299 of the format string and therefore an error occurred, the function
302 For an explanation of the terms used in this section, see
308 Interface Attribute Value
311 T} Thread safety MT-Safe env locale
314 POSIX.1-2001, POSIX.1-2008, SUSv2.
317 In principle, this function does not initialize
320 stores only the values specified.
323 should be initialized before the call.
324 Details differ a bit between different UNIX systems.
325 The glibc implementation does not touch those fields which are not
326 explicitly specified, except that it recomputes the
330 field if any of the year, month, or day elements changed.
332 .\" This function is available since libc 4.6.8.
333 .\" Linux libc4 and libc5 includes define the prototype unconditionally;
334 .\" glibc2 includes provide a prototype only when
340 .\" Before libc 5.4.13 whitespace
341 .\" (and the \(aqn\(aq and \(aqt\(aq specifications) was not handled,
342 .\" no \(aqE\(aq and \(aqO\(aq locale modifier characters were accepted,
343 .\" and the \(aqC\(aq specification was a synonym for the \(aqc\(aq specification.
345 The \(aqy\(aq (year in century) specification is taken to specify a year
346 .\" in the 20th century by libc4 and libc5.
347 .\" It is taken to be a year
348 in the range 1950\(en2049 by glibc 2.0.
349 It is taken to be a year in
350 1969\(en2068 since glibc 2.1.
351 .\" In libc4 and libc5 the code for %I is broken (fixed in glibc;
352 .\" %OI was fixed in glibc 2.2.4).
354 For reasons of symmetry, glibc tries to support for
356 the same format characters as for
358 (In most cases, the corresponding fields are parsed, but no field in
366 the ISO 8601 date format.
369 The year corresponding to the ISO week number, but without the century
373 The year corresponding to the ISO week number.
377 The day of the week as a decimal number (1\(en7, where Monday = 1).
380 The ISO 8601:1988 week number as a decimal number (1\(en53).
381 If the week (starting on Monday) containing 1 January has four or more days
382 in the new year, then it is considered week 1.
383 Otherwise, it is the last week
384 of the previous year, and the next week is week 1.
387 An RFC-822/ISO 8601 standard timezone specification.
392 Similarly, because of GNU extensions to
395 is accepted as a synonym for
404 is accepted as a synonym for
409 The number of seconds since the Epoch, 1970-01-01 00:00:00 +0000 (UTC).
410 Leap seconds are not counted unless leap second support is available.
412 The glibc implementation does not require whitespace between
413 two field descriptors.
415 The following example demonstrates the use of
421 #define _XOPEN_SOURCE
433 memset(&tm, 0, sizeof(struct tm));
434 strptime("2001\-11\-12 18:31:01", "%Y\-%m\-%d %H:%M:%S", &tm);
435 strftime(buf, sizeof(buf), "%d %b %Y %H:%M", &tm);