Skip site navigation (1)Skip section navigation (2)

FreeBSD Manual Pages

  
 
  

home | help
STRPTIME(3)		   Linux Programmer's Manual		   STRPTIME(3)

NAME
       strptime	 - convert a string representation of time to a	time tm	struc-
       ture

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	function  to  strftime(3)  and
       converts	 the  character	 string	 pointed  to  by s to values which are
       stored in the tm	structure pointed to by	tm, using the format specified
       by  format.   Here  format 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  charac-
       ters  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 for-
       mat) 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 a weekday or month name)	is to be matched, the compari-
       son is case insensitive.	 In case a number is to	 be  matched,  leading
       zeros are permitted but not required.

       %%     The % character.

       %a or %A
	      The weekday name 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 weekday number (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 twen-
	      tieth  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  charac-
       ters  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 rep-
	      resentation.

       %EY    The full alternative year	representation.

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

       %Od or %Oe
	      The day of the month using the locale's alternative numeric sym-
	      bols; 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 number of the	weekday	(Sunday=0) using the locale's alterna-
	      tive 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.

       The broken-down time structure tm is defined in _time.h_	as follows:

	   struct tm {
	       int tm_sec;	  /* seconds */
	       int tm_min;	  /* minutes */
	       int tm_hour;	  /* hours */
	       int tm_mday;	  /* day of the	month */
	       int tm_mon;	  /* month */
	       int tm_year;	  /* year */
	       int tm_wday;	  /* day of the	week */
	       int tm_yday;	  /* day in the	year */
	       int tm_isdst;	  /* daylight saving time */
	   };

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 for-
       mat string and therefore	an error occurred the function returns NULL.

CONFORMING TO
       SUSv2, POSIX.1-2001.

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.

       This function is	available since	libc 4.6.8.  Linux libc4 and libc5 in-
       cludes define the prototype unconditionally; glibc2 includes provide  a
       prototype only when _XOPEN_SOURCE or _GNU_SOURCE	are defined.

       Before  libc 5.4.13 whitespace (and the 'n' and 't' specifications) was
       not handled, no 'E' and 'O' locale modifier characters  were  accepted,
       and the 'C' specification was a synonym for the 'c' specification.

       The  'y'	 (year in century) specification is taken to specify a year in
       the 20th	century	by libc4 and libc5.  It	is taken to be 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.	Other-
	      wise,  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 strf-
       time(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 3.53 of the	Linux  man-pages  project.   A
       description  of	the project, and information about reporting bugs, can
       be found	at http://www.kernel.org/doc/man-pages/.

GNU				  2009-12-05			   STRPTIME(3)

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

Want to link to this manual page? Use this URL:
<https://www.freebsd.org/cgi/man.cgi?query=strptime&sektion=3&manpath=CentOS+7.1>

home | help