strptime(3C)
NAME
strptime - date and time conversion
SYNOPSIS
#include <time.h>
char *strptime(const char *buf, const char *format, struct
tm *tm);
Non-zeroing Behavior
cc [flag ...] file ... -D_STRPTIME_DONTZERO [library ...]
char *strptime(const char *buf, const char *format, struct
tm *tm);
DESCRIPTION
The strptime() function converts 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 argument is composed of zero or more conversion
specifications. Each conversion specification is composed of
a "%" (percent) character followed by one or two conversion
characters which specify the replacement required. One or
more white space characters (as specified by isspace(3C))
may precede or follow a conversion specification. There must
be white-space or other non-alphanumeric characters between
any two conversion specifications.
A non-zeroing version of strptime(), described below under
Non-zeroing Behavior, is provided if _STRPTIME_DONTZERO is
defined.
Conversion Specifications
The following conversion specifications are supported:
%% Same as %.
%a Day of week, using the locale's weekday names; either
the abbreviated or full name may be specified.
%A Same as %a.
%b Month, using the locale's month names; either the
abbreviated or full name may be specified.
%B Same as %b.
%c Locale's appropriate date and time representation.
%C Century number (the year divided by 100 and truncated
to an integer as a decimal number [1,99]); single
digits are preceded by 0. If %C is used without the %y
specifier, strptime() assumes the year offset is zero
in whichever century is specified. Note the behavior
of %C in the absence of %y is not specified by any of
the standards or specifications described on the stan-
dards(5) manual page, so portable applications should
not depend on it. This behavior may change in a
future release.
%d Day of month [1,31]; leading zero is permitted but not
required.
%D Date as %m/%d/%y.
%e Same as %d.
%h Same as %b.
%H Hour (24-hour clock) [0,23]; leading zero is permit-
ted but not required.
%I Hour (12-hour clock) [1,12]; leading zero is permit-
ted but not required.
%j Day number of the year [1,366]; leading zeros are
permitted but not required.
%m Month number [1,12]; leading zero is permitted but not
required.
%M Minute [0-59]; leading zero is permitted but not
required.
%n Any white space.
%p Locale's equivalent of either a.m. or p.m.
%r Appropriate time representation in the 12-hour clock
format with %p.
%R Time as %H:%M.
%S Seconds [0,61]; leading zero is permitted but not
required. The range of values is [00,61] rather than
[00,59] to allow for the occasional leap second and
even more occasional double leap second.
%t Any white space.
%T Time as %H:%M:%S.
%U Week number of the year as a decimal number [0,53],
with Sunday as the first day of the week; leading
zeros are permitted but not required.
%w Weekday as a decimal number [0,6], with 0 representing
Sunday.
%W Week number of the year as a decimal number [0,53],
with Monday as the first day of the week; leading
zero is permitted but not required.
%x Locale's appropriate date representation.
%X Locale's appropriate time representation.
%y The year within century. When a century is not other-
wise specified, values in the range 69-99 refer to
years in the twentieth century (1969 to 1999
inclusive); values in the range 00-68 refer to years
in the twenty-first century (2000 to 2068 inclusive).
Leading zeros are permitted but not required.
%Y Year, including the century (for example, 1993) [1-
9999].
%Z Timezone name or no characters if no time zone infor-
mation exists. Local timezone information is used as
though strptime() called tzset() (see ctime(3C)).
Errors may not be detected. This behavior is subject
to change in a future release.
Modified Conversion Specifications
Some conversion specifications can be modified by the E and
O modifier characters to indicate that an alternate format
or specification should be used rather than the one normally
used by the unmodified specification. If the alternate for-
mat or specification does not exist in the current locale,
the behavior will be as if the unmodified conversion specif-
ication were used.
%Ec Locale's alternate appropriate date and time represen-
tation.
%EC Name of the base year (era) in the locale's alternate
representation.
%Ex Locale's alternate date representation.
%EX Locale's alternate time representation.
%Ey Offset from %EC (year only) in the locale's alternate
representation.
%EY Full alternate year representation.
%Od Day of the month using the locale's alternate numeric
symbols.
%Oe Same as %Od.
%OH Hour (24-hour clock) using the locale's alternate
numeric symbols.
%OI Hour (12-hour clock) using the locale's alternate
numeric symbols.
%Om Month using the locale's alternate numeric symbols.
%OM Minutes using the locale's alternate numeric symbols.
%OS Seconds using the locale's alternate numeric symbols.
%OU Week number of the year (Sunday as the first day of
the week) using the locale's alternate numeric sym-
bols.
%Ow Number of the weekday (Sunday=0) using the locale's
alternate numeric symbols.
%OW Week number of the year (Monday as the first day of
the week) using the locale's alternate numeric sym-
bols.
%Oy Year (offset from %C) in the locale's alternate
representation and using the locale's alternate
numeric symbols.
General Specifications
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 specification, the specification fails, and
the differing and subsequent characters remain unscanned.
A series of 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.
White space is defined by isspace(3C).
Any other conversion specification is executed by scanning
characters until a character matching the next specification
is scanned, or until no more characters can be scanned.
These characters, except the one matching the next specifi-
cation, are then compared to the locale values associated
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. If no match is
found, strptime() fails and no more characters are scanned.
The month names, weekday names, era names, and alternate
numeric symbols can consist of any combination of upper and
lower case letters. The user can request that the input
date or time specification be in a specific language by set-
ting the LC_TIME category using setlocale(3C).
Non-zeroing Behavior
In addition to the behavior described above by various stan-
dards, the Solaris implementation of strptime() provides the
following extensions. These may change at any time in the
future. Portable applications should not depend on these
extended features:
o If _STRPTIME_DONTZERO is not defined, the tm struct is
zeroed on entry and strptime() updates the fields of
the tm struct associated with the specifiers in the
format string.
o If _STRPTIME_DONTZERO is defined, strptime() does not
zero the tm struct on entry. Additionally, for some
specifiers, strptime() will use some values in the
input tm struct to recalculate the date and re-assign
the appropriate members of the tm struct.
The following describes extended features regardless of
whether _STRPTIME_DONTZERO is defined or not defined:
o If %j is specified, tm_yday is set; if year is given,
and if month and day are not given, strptime() calcu-
lates and sets tm_mon, tm_mday, and tm_year.
o If %U or %W is specified and if weekday and year are
given and month and day of month are not given,
strptime() calculates and sets tm_mon, tm_mday,
tm_wday, and tm_year.
The following describes extended features when
_STRPTIME_DONTZERO is not defined:
o If %C is specified and %y is not specified,
strptime()assumes 0 as the year offset, then calcu-
lates the year, and assigns tm_year.
The following describes extended features when
_STRPTIME_DONTZERO is defined:
o If %C is specified and %y is not specified, strptime()
assumes the year offset of the year value of the
tm_year member of the input tm struct, then calculates
the year and assigns tm_year.
o If %j is specified and neither %y, %Y, nor %C are
specified, and neither month nor day of month are
specified, strptime() assumes the year value given by
the value of the tm_year field of the input tm struct.
Then, in addition to setting tm_yday, strptime() uses
day-of-year and year values to calculate the month and
day-of-month, and assigns tm_month and tm_mday.
o If %U or %W is specified, and if weekday and/or year
are not given, and month and day of month are not
given, strptime() will assume the weekday value and/or
the year value as the value of the tm_wday field
and/or tm_year field of the input tm struct. Then,
strptime() will calculate the month and day-of-month
and assign tm_month, tm_mday, and/or tm_year.
o If %p is specified and if hour is not specified,
strptime() will reference, and if needed, update the
tm_hour member. If the am_pm input is p.m. and the
input tm_hour value is between 0 - 11, strptime() will
add 12 hours and update tm_hour. If the am_pm input
is a.m. and input tm_hour value is between 12 - 23,
strptime() will subtract 12 hours and update tm_hour.
RETURN VALUES
Upon successful completion, strptime() returns a pointer to
the character following the last character parsed. Other-
wise, a null pointer is returned.
USAGE
Several "same as" formats, and the special processing of
white-space characters are provided in order to ease the use
of identical format strings for strftime(3C) and
strptime().
The strptime() function tries to calculate tm_year, tm_mon,
and tm_mday when given incomplete input. This allows the
struct tm created by strptime() to be passed to mktime(3C)
to produce a time_t value for dates and times that are
representable by a time_t. As an example, since mktime()
ignores tm_yday, strptime() calculates tm_mon and tm_mday as
well as filling in tm_yday when %j is specified without oth-
erwise specifying a month and day within month.
ATTRIBUTES
See attributes(5) for descriptions of the following attri-
butes:
____________________________________________________________
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
|_____________________________|_____________________________|
| MT-Level | MT-Safe |
|_____________________________|_____________________________|
| CSI | Enabled |
|_____________________________|_____________________________|
SEE ALSO
ctime(3C), getdate(3C), isspace(3C), mktime(3C),
setlocale(3C), strftime(3C), attributes(5), environ(5),
standards(5)
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