NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | ATTRIBUTES | CONFORMING TO | NOTES | EXAMPLE | SEE ALSO | COLOPHON

STRPTIME(3)               Linux Programmer's Manual              STRPTIME(3)

NAME         top

       strptime  -  convert  a  string  representation  of time to a time tm
       structure

SYNOPSIS         top

       #define _XOPEN_SOURCE       /* See feature_test_macros(7) */
       #include <time.h>

       char *strptime(const char *s, const char *format, struct tm *tm);

DESCRIPTION         top

       The strptime() function is the converse of strftime(3); it converts
       the character string pointed to by s to values which are stored in
       the "broken-down time" structure pointed to by tm, using the format
       specified by format.

       The broken-down time structure tm is defined in <time.h> as follows:

           struct tm {
               int tm_sec;    /* Seconds (0-60) */
               int tm_min;    /* Minutes (0-59) */
               int tm_hour;   /* Hours (0-23) */
               int tm_mday;   /* Day of the month (1-31) */
               int tm_mon;    /* Month (0-11) */
               int tm_year;   /* Year - 1900 */
               int tm_wday;   /* Day of the week (0-6, Sunday = 0) */
               int tm_yday;   /* Day in the year (0-365, 1 Jan = 0) */
               int tm_isdst;  /* Daylight saving time */
           };

       For more details on the tm structure, see ctime(3).

       The format argument is a character string that consists of field
       descriptors and text characters, reminiscent of scanf(3).  Each field
       descriptor consists of a % character followed by another character
       that specifies the replacement for the field descriptor.  All other
       characters in the format string must have a matching character in the
       input string, except for whitespace, which matches zero or more
       whitespace characters in the input string.  There should be white‐
       space or other alphanumeric characters between any two field
       descriptors.

       The strptime() function processes the input string from left to
       right.  Each of the three possible input elements (whitespace,
       literal, or format) are handled one after the other.  If the input
       cannot be matched to the format string, the function stops.  The
       remainder of the format and input strings are not processed.

       The supported input field descriptors are listed below.  In case a
       text string (such as the name of a day of the week or a month name)
       is to be matched, the comparison is case insensitive.  In case a
       number is to be matched, leading zeros are permitted but not
       required.

       %%     The % character.

       %a or %A
              The name of the day of the week according to the current
              locale, in abbreviated form or the full name.

       %b or %B or %h
              The month name according to the current locale, in abbreviated
              form or the full name.

       %c     The date and time representation for the current locale.

       %C     The century number (0-99).

       %d or %e
              The day of month (1-31).

       %D     Equivalent to %m/%d/%y.  (This is the American style date,
              very confusing to non-Americans, especially since %d/%m/%y is
              widely used in Europe.  The ISO 8601 standard format is
              %Y-%m-%d.)

       %H     The hour (0-23).

       %I     The hour on a 12-hour clock (1-12).

       %j     The day number in the year (1-366).

       %m     The month number (1-12).

       %M     The minute (0-59).

       %n     Arbitrary whitespace.

       %p     The locale's equivalent of AM or PM.  (Note: there may be
              none.)

       %r     The 12-hour clock time (using the locale's AM or PM).  In the
              POSIX locale equivalent to %I:%M:%S %p.  If t_fmt_ampm is
              empty in the LC_TIME part of the current locale, then the
              behavior is undefined.

       %R     Equivalent to %H:%M.

       %S     The second (0-60; 60 may occur for leap seconds; earlier also
              61 was allowed).

       %t     Arbitrary whitespace.

       %T     Equivalent to %H:%M:%S.

       %U     The week number with Sunday the first day of the week (0-53).
              The first Sunday of January is the first day of week 1.

       %w     The ordinal number of the day of the week (0-6), with Sunday =
              0.

       %W     The week number with Monday the first day of the week (0-53).
              The first Monday of January is the first day of week 1.

       %x     The date, using the locale's date format.

       %X     The time, using the locale's time format.

       %y     The year within century (0-99).  When a century is not
              otherwise specified, values in the range 69-99 refer to years
              in the twentieth century (1969-1999); values in the range
              00-68 refer to years in the twenty-first century (2000-2068).

       %Y     The year, including century (for example, 1991).

       Some field descriptors can be modified by the E or O modifier
       characters to indicate that an alternative format or specification
       should be used.  If the alternative format or specification does not
       exist in the current locale, the unmodified field descriptor is used.

       The E modifier specifies that the input string may contain
       alternative locale-dependent versions of the date and time
       representation:

       %Ec    The locale's alternative date and time representation.

       %EC    The name of the base year (period) in the locale's alternative
              representation.

       %Ex    The locale's alternative date representation.

       %EX    The locale's alternative time representation.

       %Ey    The offset from %EC (year only) in the locale's alternative
              representation.

       %EY    The full alternative year representation.

       The O modifier specifies that the numerical input may be in an
       alternative locale-dependent format:

       %Od or %Oe
              The day of the month using the locale's alternative numeric
              symbols; leading zeros are permitted but not required.

       %OH    The hour (24-hour clock) using the locale's alternative
              numeric symbols.

       %OI    The hour (12-hour clock) using the locale's alternative
              numeric symbols.

       %Om    The month using the locale's alternative numeric symbols.

       %OM    The minutes using the locale's alternative numeric symbols.

       %OS    The seconds using the locale's alternative numeric symbols.

       %OU    The week number of the year (Sunday as the first day of the
              week) using the locale's alternative numeric symbols.

       %Ow    The ordinal number of the day of the week (Sunday=0),
               using the locale's alternative numeric symbols.

       %OW    The week number of the year (Monday as the first day of the
              week) using the locale's alternative numeric symbols.

       %Oy    The year (offset from %C) using the locale's alternative
              numeric symbols.

RETURN VALUE         top

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

ATTRIBUTES         top

       For an explanation of the terms used in this section, see
       attributes(7).

       ┌───────────┬───────────────┬────────────────────┐
       │Interface  Attribute     Value              │
       ├───────────┼───────────────┼────────────────────┤
       │strptime() │ Thread safety │ MT-Safe env locale │
       └───────────┴───────────────┴────────────────────┘

CONFORMING TO         top

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

NOTES         top

       In principle, this function does not initialize tm but stores only
       the values specified.  This means that tm should be initialized
       before the call.  Details differ a bit between different UNIX
       systems.  The glibc implementation does not touch those fields which
       are not explicitly specified, except that it recomputes the tm_wday
       and tm_yday field if any of the year, month, or day elements changed.

       The 'y' (year in century) specification is taken to specify a year in
       the range 1950-2049 by glibc 2.0.  It is taken to be a year in
       1969-2068 since glibc 2.1.

   Glibc notes
       For reasons of symmetry, glibc tries to support for strptime() the
       same format characters as for strftime(3).  (In most cases, the
       corresponding fields are parsed, but no field in tm is changed.)
       This leads to

       %F     Equivalent to %Y-%m-%d, the ISO 8601 date format.

       %g     The year corresponding to the ISO week number, but without the
              century (0-99).

       %G     The year corresponding to the ISO week number.  (For example,
              1991.)

       %u     The day of the week as a decimal number (1-7, where Monday =
              1).

       %V     The ISO 8601:1988 week number as a decimal number (1-53).  If
              the week (starting on Monday) containing 1 January has four or
              more days in the new year, then it is considered week 1.
              Otherwise, it is the last week of the previous year, and the
              next week is week 1.

       %z     An RFC-822/ISO 8601 standard timezone specification.

       %Z     The timezone name.

       Similarly, because of GNU extensions to strftime(3), %k is accepted
       as a synonym for %H, and %l should be accepted as a synonym for %I,
       and %P is accepted as a synonym for %p.  Finally

       %s     The number of seconds since the Epoch, 1970-01-01 00:00:00
              +0000 (UTC).  Leap seconds are not counted unless leap second
              support is available.

       The glibc implementation does not require whitespace between two
       field descriptors.

EXAMPLE         top

       The following example demonstrates the use of strptime() and
       strftime(3).

       #define _XOPEN_SOURCE
       #include <stdio.h>
       #include <stdlib.h>
       #include <string.h>
       #include <time.h>

       int
       main(void)
       {
           struct tm tm;
           char buf[255];

           memset(&tm, 0, sizeof(struct tm));
           strptime("2001-11-12 18:31:01", "%Y-%m-%d %H:%M:%S", &tm);
           strftime(buf, sizeof(buf), "%d %b %Y %H:%M", &tm);
           puts(buf);
           exit(EXIT_SUCCESS);
       }

SEE ALSO         top

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

COLOPHON         top

       This page is part of release 4.07 of the Linux man-pages project.  A
       description of the project, information about reporting bugs, and the
       latest version of this page, can be found at
       https://www.kernel.org/doc/man-pages/.

GNU                              2015-08-08                      STRPTIME(3)