1STRPTIME(3)                Linux Programmer's Manual               STRPTIME(3)
2
3
4

NAME

6       strptime  - convert a string representation of time to a time tm struc‐
7       ture
8

SYNOPSIS

10       #define _XOPEN_SOURCE       /* See feature_test_macros(7) */
11       #include <time.h>
12
13       char *strptime(const char *s, const char *format, struct tm *tm);
14

DESCRIPTION

16       The strptime() function is the converse of strftime(3); it converts the
17       character  string  pointed  to  by  s to values which are stored in the
18       "broken-down time" structure pointed to by tm, using the format  speci‐
19       fied by format.
20
21       The broken-down time structure tm is defined in <time.h> as follows:
22
23           struct tm {
24               int tm_sec;    /* Seconds (0-60) */
25               int tm_min;    /* Minutes (0-59) */
26               int tm_hour;   /* Hours (0-23) */
27               int tm_mday;   /* Day of the month (1-31) */
28               int tm_mon;    /* Month (0-11) */
29               int tm_year;   /* Year - 1900 */
30               int tm_wday;   /* Day of the week (0-6, Sunday = 0) */
31               int tm_yday;   /* Day in the year (0-365, 1 Jan = 0) */
32               int tm_isdst;  /* Daylight saving time */
33           };
34
35       For more details on the tm structure, see ctime(3).
36
37       The  format  argument  is  a  character  string  that consists of field
38       descriptors and text characters, reminiscent of scanf(3).   Each  field
39       descriptor consists of a % character followed by another character that
40       specifies the replacement for the field descriptor.  All other  charac‐
41       ters  in  the format string must have a matching character in the input
42       string, except for whitespace, which matches zero  or  more  whitespace
43       characters  in  the  input string.  There should be whitespace or other
44       alphanumeric characters between any two field descriptors.
45
46       The strptime() function processes the input string from left to  right.
47       Each of the three possible input elements (whitespace, literal, or for‐
48       mat) are handled one after the other.  If the input cannot  be  matched
49       to  the format string, the function stops.  The remainder of the format
50       and input strings are not processed.
51
52       The supported input field descriptors are listed below.  In case a text
53       string (such as the name of a day of the week or a month name) is to be
54       matched, the comparison is case insensitive.  In case a number is to be
55       matched, leading zeros are permitted but not required.
56
57       %%     The % character.
58
59       %a or %A
60              The name of the day of the week according to the current locale,
61              in abbreviated form or the full name.
62
63       %b or %B or %h
64              The month name according to the current locale,  in  abbreviated
65              form or the full name.
66
67       %c     The date and time representation for the current locale.
68
69       %C     The century number (0–99).
70
71       %d or %e
72              The day of month (1–31).
73
74       %D     Equivalent  to %m/%d/%y.  (This is the American style date, very
75              confusing to non-Americans, especially since %d/%m/%y is  widely
76              used in Europe.  The ISO 8601 standard format is %Y-%m-%d.)
77
78       %H     The hour (0–23).
79
80       %I     The hour on a 12-hour clock (1–12).
81
82       %j     The day number in the year (1–366).
83
84       %m     The month number (1–12).
85
86       %M     The minute (0–59).
87
88       %n     Arbitrary whitespace.
89
90       %p     The locale's equivalent of AM or PM.  (Note: there may be none.)
91
92       %r     The  12-hour  clock  time (using the locale's AM or PM).  In the
93              POSIX locale equivalent to %I:%M:%S %p.  If t_fmt_ampm is  empty
94              in  the LC_TIME part of the current locale, then the behavior is
95              undefined.
96
97       %R     Equivalent to %H:%M.
98
99       %S     The second (0–60; 60 may occur for leap seconds; earlier also 61
100              was allowed).
101
102       %t     Arbitrary whitespace.
103
104       %T     Equivalent to %H:%M:%S.
105
106       %U     The  week  number  with Sunday the first day of the week (0–53).
107              The first Sunday of January is the first day of week 1.
108
109       %w     The ordinal number of the day of the week (0–6), with  Sunday  =
110              0.
111
112       %W     The  week  number  with Monday the first day of the week (0–53).
113              The first Monday of January is the first day of week 1.
114
115       %x     The date, using the locale's date format.
116
117       %X     The time, using the locale's time format.
118
119       %y     The year within century (0–99).  When a century is not otherwise
120              specified, values in the range 69–99 refer to years in the twen‐
121              tieth century (1969–1999); values in the range  00–68  refer  to
122              years in the twenty-first century (2000–2068).
123
124       %Y     The year, including century (for example, 1991).
125
126       Some  field  descriptors can be modified by the E or O modifier charac‐
127       ters to indicate that an alternative format or specification should  be
128       used.  If the alternative format or specification does not exist in the
129       current locale, the unmodified field descriptor is used.
130
131       The E modifier specifies that the input string may contain  alternative
132       locale-dependent versions of the date and time representation:
133
134       %Ec    The locale's alternative date and time representation.
135
136       %EC    The  name  of the base year (period) in the locale's alternative
137              representation.
138
139       %Ex    The locale's alternative date representation.
140
141       %EX    The locale's alternative time representation.
142
143       %Ey    The offset from %EC (year only) in the locale's alternative rep‐
144              resentation.
145
146       %EY    The full alternative year representation.
147
148       The O modifier specifies that the numerical input may be in an alterna‐
149       tive locale-dependent format:
150
151       %Od or %Oe
152              The day of the month using the locale's alternative numeric sym‐
153              bols; leading zeros are permitted but not required.
154
155       %OH    The  hour (24-hour clock) using the locale's alternative numeric
156              symbols.
157
158       %OI    The hour (12-hour clock) using the locale's alternative  numeric
159              symbols.
160
161       %Om    The month using the locale's alternative numeric symbols.
162
163       %OM    The minutes using the locale's alternative numeric symbols.
164
165       %OS    The seconds using the locale's alternative numeric symbols.
166
167       %OU    The  week  number  of  the  year (Sunday as the first day of the
168              week) using the locale's alternative numeric symbols.
169
170       %Ow    The ordinal number of the day of the week (Sunday=0),
171               using the locale's alternative numeric symbols.
172
173       %OW    The week number of the year (Monday as  the  first  day  of  the
174              week) using the locale's alternative numeric symbols.
175
176       %Oy    The year (offset from %C) using the locale's alternative numeric
177              symbols.
178

RETURN VALUE

180       The return value of the function is a pointer to  the  first  character
181       not processed in this function call.  In case the input string contains
182       more characters than required by the format string,  the  return  value
183       points  right  after  the  last  consumed input character.  In case the
184       whole input string is consumed, the return value  points  to  the  null
185       byte at the end of the string.  If strptime() fails to match all of the
186       format string and therefore an error  occurred,  the  function  returns
187       NULL.
188

ATTRIBUTES

190       For   an   explanation   of   the  terms  used  in  this  section,  see
191       attributes(7).
192
193       ┌───────────┬───────────────┬────────────────────┐
194Interface  Attribute     Value              
195       ├───────────┼───────────────┼────────────────────┤
196strptime() │ Thread safety │ MT-Safe env locale │
197       └───────────┴───────────────┴────────────────────┘

CONFORMING TO

199       POSIX.1-2001, POSIX.1-2008, SUSv2.
200

NOTES

202       In principle, this function does not initialize tm but stores only  the
203       values  specified.  This means that tm should be initialized before the
204       call.  Details differ a bit between different UNIX systems.  The  glibc
205       implementation  does  not  touch  those fields which are not explicitly
206       specified, except that it recomputes the tm_wday and tm_yday  field  if
207       any of the year, month, or day elements changed.
208
209       The  'y'  (year in century) specification is taken to specify a year in
210       the range 1950–2049 by glibc  2.0.   It  is  taken  to  be  a  year  in
211       1969–2068 since glibc 2.1.
212
213   Glibc notes
214       For reasons of symmetry, glibc tries to support for strptime() the same
215       format characters as for strftime(3).  (In most cases, the  correspond‐
216       ing fields are parsed, but no field in tm is changed.)  This leads to
217
218       %F     Equivalent to %Y-%m-%d, the ISO 8601 date format.
219
220       %g     The  year  corresponding to the ISO week number, but without the
221              century (0–99).
222
223       %G     The year corresponding to the ISO week  number.   (For  example,
224              1991.)
225
226       %u     The day of the week as a decimal number (1–7, where Monday = 1).
227
228       %V     The  ISO  8601:1988  week number as a decimal number (1–53).  If
229              the week (starting on Monday) containing 1 January has  four  or
230              more days in the new year, then it is considered week 1.  Other‐
231              wise, it is the last week of the previous  year,  and  the  next
232              week is week 1.
233
234       %z     An RFC-822/ISO 8601 standard timezone specification.
235
236       %Z     The timezone name.
237
238       Similarly,  because of GNU extensions to strftime(3), %k is accepted as
239       a synonym for %H, and %l should be accepted as a synonym for %I, and %P
240       is accepted as a synonym for %p.  Finally
241
242       %s     The number of seconds since the Epoch, 1970-01-01 00:00:00 +0000
243              (UTC).  Leap seconds are not counted unless leap second  support
244              is available.
245
246       The  glibc implementation does not require whitespace between two field
247       descriptors.
248

EXAMPLES

250       The following example demonstrates the  use  of  strptime()  and  strf‐
251       time(3).
252
253       #define _XOPEN_SOURCE
254       #include <stdio.h>
255       #include <stdlib.h>
256       #include <string.h>
257       #include <time.h>
258
259       int
260       main(void)
261       {
262           struct tm tm;
263           char buf[255];
264
265           memset(&tm, 0, sizeof(struct tm));
266           strptime("2001-11-12 18:31:01", "%Y-%m-%d %H:%M:%S", &tm);
267           strftime(buf, sizeof(buf), "%d %b %Y %H:%M", &tm);
268           puts(buf);
269           exit(EXIT_SUCCESS);
270       }
271

SEE ALSO

273       time(2), getdate(3), scanf(3), setlocale(3), strftime(3)
274

COLOPHON

276       This  page  is  part of release 5.07 of the Linux man-pages project.  A
277       description of the project, information about reporting bugs,  and  the
278       latest     version     of     this    page,    can    be    found    at
279       https://www.kernel.org/doc/man-pages/.
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283GNU                               2020-06-09                       STRPTIME(3)
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