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


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

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


   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

   %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  =

   %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

   %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

   %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

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

   %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


   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


   For   an   explanation   of   the  terms  used  in  this  section,  see

   Interface   Attribute      Value              
   strptime()  Thread safety  MT-Safe env locale 


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


   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,

   %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


   The   following   example   demonstrates  the  use  of  strptime()  and

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

       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);


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


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