STRPTIME(3C)STRPTIME(3C)NAMEstrptime - date and time conversion
SYNOPSIS
#include <time.h>
char *strptime(const char *restrict buf,
const char *restrict format, struct tm *restrict tm);
Non-zeroing Behavior
cc [flag...] file... -D_STRPTIME_DONTZERO [library...]
#include <time.h>
char *strptime(const char *restrict buf,
const char *restrict format, struct tm *restrict 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 specifica‐
tions. 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 speci‐
fied 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 abbre‐
viated 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 inte‐
ger 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 standards(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 permitted but not
required.
%I
Hour (12-hour clock) [1,12]; leading zero is permitted 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.
SUSv3
%S
Seconds [0,60]; leading zero is permitted but not required. The
range of values is [00,60] rather than [00,59] to allow for the
occasional leap second.
Default and other standards
%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 sec‐
ond.
%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 zero is 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
Year within century. When a century is not otherwise 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).
%Y
Year, including the century (for example, 1993).
%Z
Time zone name or no characters if no time zone exists.
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 specifica‐
tion. If the alternate format or specification does not exist in the
current locale, the behavior will be as if the unmodified conversion
specification were used.
%Ec
Locale's alternate appropriate date and time representation.
%EC
Name of the base year (era) in the locale's alternate represen‐
tation.
%Ex
Locale's alternate date representation.
%EX
Locale's alternate time representation.
%Ey
Offset from %EC (year only) in the locale's alternate represen‐
tation.
%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 sym‐
bols.
%OI
Hour (12-hour clock) using the locale's alternate numeric sym‐
bols.
%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 symbols.
%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 symbols.
%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 specification, 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 correspond‐
ing 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 sym‐
bols 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 setting the LC_TIME category using setlocale(3C).
Non-zeroing Behavior
In addition to the behavior described above by various standards, 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 _STRP‐
TIME_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() calculates 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() calcu‐
lates 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, strp‐
time()assumes 0 as the year offset, then calculates 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 cal‐
culate 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 charac‐
ter following the last character parsed. Otherwise, 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 attributes:
┌────────────────────┬───────────────────┐
│ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├────────────────────┼───────────────────┤
│CSI │ Enabled │
├────────────────────┼───────────────────┤
│Interface Stability │ Committed │
├────────────────────┼───────────────────┤
│MT-Level │ MT-Safe │
├────────────────────┼───────────────────┤
│Standard │ See standards(5). │
└────────────────────┴───────────────────┘
SEE ALSOctime(3C), getdate(3C), isspace(3C), mktime(3C), setlocale(3C), strf‐
time(3C), attributes(5), environ(5), standards(5)
Aug 27, 2007 STRPTIME(3C)
