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

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  twenti-
	      eth 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  con-
       tains  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).

       +-----------+---------------+--------------------+
       |Interface  | Attribute	   | Value		|
       +-----------+---------------+--------------------+
       |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 explic-
       itly 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  corre-
       sponding 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

       This  page is part of release 4.15 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
								    2017-09-15							       STRPTIME(3)