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NAME

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

SYNOPSIS

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

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

DESCRIPTION

       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 whitespace 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

       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

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

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

CONFORMING TO

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

NOTES

       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

       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

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

COLOPHON

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