STRPTIME(P) POSIX Programmer's Manual STRPTIME(P)NAMEstrptime - date and time conversion
SYNOPSIS
#include <time.h>
char *strptime(const char *restrict buf, const char *restrict format,
struct tm *restrict tm);
DESCRIPTION
The strptime() function shall convert the character string pointed to
by buf to values which are stored in the tm structure pointed to by tm,
using the format specified by format.
The format is composed of zero or more directives. Each directive is
composed of one of the following: one or more white-space characters
(as specified by isspace()); an ordinary character (neither '%' nor a
white-space character); or a conversion specification. Each conversion
specification is composed of a '%' character followed by a conversion
character which specifies the replacement required. The application
shall ensure that there is white-space or other non-alphanumeric char‐
acters between any two conversion specifications. The following conver‐
sion specifications are supported:
%a The day of the week, using the locale's weekday names; either
the abbreviated or full name may be specified.
%A Equivalent to %a .
%b The month, using the locale's month names; either the abbrevi‐
ated or full name may be specified.
%B Equivalent to %b .
%c Replaced by the locale's appropriate date and time representa‐
tion.
%C The century number [00,99]; leading zeros are permitted but not
required.
%d The day of the month [01,31]; leading zeros are permitted but
not required.
%D The date as %m / %d / %y .
%e Equivalent to %d .
%h Equivalent to %b .
%H The hour (24-hour clock) [00,23]; leading zeros are permitted
but not required.
%I The hour (12-hour clock) [01,12]; leading zeros are permitted
but not required.
%j The day number of the year [001,366]; leading zeros are permit‐
ted but not required.
%m The month number [01,12]; leading zeros are permitted but not
required.
%M The minute [00,59]; leading zeros are permitted but not
required.
%n Any white space.
%p The locale's equivalent of a.m or p.m.
%r 12-hour clock time using the AM/PM notation if t_fmt_ampm is not
an empty string in the LC_TIME portion of the current locale; in
the POSIX locale, this shall be equivalent to %I : %M : %S %p .
%R The time as %H : %M .
%S The seconds [00,60]; leading zeros are permitted but not
required.
%t Any white space.
%T The time as %H : %M : %S .
%U The week number of the year (Sunday as the first day of the
week) as a decimal number [00,53]; leading zeros are permitted
but not required.
%w The weekday as a decimal number [0,6], with 0 representing Sun‐
day; leading zeros are permitted but not required.
%W The week number of the year (Monday as the first day of the
week) as a decimal number [00,53]; leading zeros are permitted
but not required.
%x The date, using the locale's date format.
%X The time, using the locale's time format.
%y The year within century. When a century is not otherwise speci‐
fied, values in the range [69,99] shall refer to years 1969 to
1999 inclusive, and values in the range [00,68] shall refer to
years 2000 to 2068 inclusive; leading zeros shall be permitted
but shall not be required.
Note:
It is expected that in a future version of IEEE Std 1003.1-2001
the default century inferred from a 2-digit year will change.
(This would apply to all commands accepting a 2-digit year as
input.)
%Y The year, including the century (for example, 1988).
%% Replaced by % .
Modified Conversion Specifiers
Some conversion specifiers can be modified by the E and O modifier
characters to indicate that an alternative format or specification
should be used rather than the one normally used by the unmodified con‐
version specifier. If the alternative format or specification does not
exist in the current locale, the behavior shall be as if the unmodified
conversion specification were used.
%Ec The locale's alternative appropriate date and time representa‐
tion.
%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.
%Od The day of the month using the locale's alternative numeric sym‐
bols; leading zeros are permitted but not required.
%Oe Equivalent to %Od .
%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.
A conversion specification composed of white-space characters is exe‐
cuted by scanning input up to the first character that is not white-
space (which remains unscanned), or until no more characters can be
scanned.
A conversion specification that is an ordinary character is executed by
scanning the next character from the buffer. If the character scanned
from the buffer differs from the one comprising the directive, the
directive fails, and the differing and subsequent characters remain
unscanned.
A series of conversion specifications composed of %n , %t , white-space
characters, or any combination is executed by scanning up to the first
character that is not white space (which remains unscanned), or until
no more characters can be scanned.
Any other conversion specification is executed by scanning characters
until a character matching the next directive is scanned, or until no
more characters can be scanned. These characters, except the one match‐
ing the next directive, are then compared to the locale values associ‐
ated with the conversion specifier. If a match is found, values for the
appropriate tm structure members are set to values corresponding to the
locale information. Case is ignored when matching items in buf such as
month or weekday names. If no match is found, strptime() fails and no
more characters are scanned.
RETURN VALUE
Upon successful completion, strptime() shall return a pointer to the
character following the last character parsed. Otherwise, a null
pointer shall be returned.
ERRORS
No errors are defined.
The following sections are informative.
EXAMPLES
None.
APPLICATION USAGE
Several "equivalent to" formats and the special processing of white-
space characters are provided in order to ease the use of identical
format strings for strftime() and strptime().
Applications should use %Y (4-digit years) in preference to %y (2-digit
years).
It is unspecified whether multiple calls to strptime() using the same
tm structure will update the current contents of the structure or over‐
write all contents of the structure. Conforming applications should
make a single call to strptime() with a format and all data needed to
completely specify the date and time being converted.
RATIONALE
None.
FUTURE DIRECTIONS
The strptime() function is expected to be mandatory in the next version
of this volume of IEEE Std 1003.1-2001.
SEE ALSOscanf() , strftime() , time() , the Base Definitions volume of
IEEE Std 1003.1-2001, <time.h>
COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group. In the
event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online
at http://www.opengroup.org/unix/online.html .
IEEE/The Open Group 2003 STRPTIME(P)
