NAME
strptime —
converts a character string
to a time value
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#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 string consists of zero or more conversion
specifications, whitespace characters as defined by
isspace(), and ordinary characters. All ordinary characters
in
format are compared directly against the
corresponding characters in
buf; comparisons which fail
will cause
strptime() to fail. Whitespace characters in
format match any number of whitespace characters in
buf, including none.
A conversion specification consists of a percent sign
‘
%
’ followed by one or two conversion
characters which specify the replacement required. There must be white-space
or other non-alphanumeric characters between any two conversion
specifications.
Conversion of alphanumeric strings (such as month and weekday names) is done
without regard to case. Conversion specifications which cannot be matched will
cause
strptime() to fail.
The LC_TIME category defines the locale values for the conversion
specifications. The following conversion specifications are supported:
-
-
- %a
- the day of week, using the locale's weekday names; either
the abbreviated or full name may be specified.
-
-
- %A
- the same as %a.
-
-
- %b
- the month, using the locale's month names; either the
abbreviated or full name may be specified.
-
-
- %B
- the same as %b.
-
-
- %c
- the date and time, using the locale's date and time
format.
-
-
- %C
- the century number [0,99]; leading zeros are permitted but
not required. This conversion should be used in conjunction with the %y
conversion.
-
-
- %d
- the day of month [1,31]; leading zeros are permitted but
not required.
-
-
- %D
- the date as %m/%d/%y.
-
-
- %e
- the same as %d.
-
-
- %F
- the date as %Y-%m-%d (the ISO 8601 date format).
-
-
- %g
- the year corresponding to the ISO week number, without the
century. (A NetBSD extension.)
-
-
- %G
- the year corresponding to the ISO week number, with the
century. (A NetBSD extension.)
-
-
- %h
- the same as %b.
-
-
- %H
- the hour (24-hour clock) [0,23]; leading zeros are
permitted but not required.
-
-
- %I
- the hour (12-hour clock) [1,12]; leading zeros are
permitted but not required.
-
-
- %j
- the day number of the year [1,366]; leading zeros are
permitted but not required.
-
-
- %k
- the same as %H.
-
-
- %l
- the same as %I.
-
-
- %m
- the month number [1,12]; leading zeros are permitted but
not required.
-
-
- %M
- the minute [0,59]; leading zeros are permitted but not
required.
-
-
- %n
- any white-space, including none.
-
-
- %p
- the locale's equivalent of a.m. or p.m.
-
-
- %r
- the time (12-hour clock) with %p, using the locale's time
format.
-
-
- %R
- the time as %H:%M.
-
-
- %S
- the seconds [0,60]; leading zeros are permitted but not
required.
-
-
- %s
- the number of seconds since the Epoch, UTC (see
mktime(3)). (A
NetBSD extension.)
-
-
- %t
- any white-space, including none.
-
-
- %T
- the time as %H:%M:%S.
-
-
- %u
- the day of the week as a decimal number, where Monday = 1.
(A NetBSD extension.)
-
-
- %U
- the week number of the year (Sunday as the first day of the
week) as a decimal number [0,53]; leading zeros are permitted but not
required. All days in a year preceding the first Sunday are considered to
be in week 0.
-
-
- %V
- the ISO 8601:1988 week number as a decimal number. If the
week (starting on Monday) that contains January 1 has more than three days
in the new year, then it is considered the first week of the year. If it
has fewer than four days in the new year, then it is considered the last
week of the previous year. Weeks are numbered from 1 to 53. (A
NetBSD extension.)
-
-
- %w
- the weekday as a decimal number [0,6], with 0 representing
Sunday; 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 [0,53]; leading zeros are permitted but not
required. All days in a year preceding the first Monday are considered to
be in week 0.
-
-
- %x
- the date, using the locale's date format.
-
-
- %X
- the time, using the locale's time format.
-
-
- %y
- the year within the 20th century [69,99] or the 21st
century [0,68]; leading zeros are permitted but not required. If specified
in conjunction with %C, specifies the year [0,99] within that
century.
-
-
- %Y
- the year, including the century (i.e., 1996).
-
-
- %z
- an ISO 8601, RFC-2822, or RFC-3339 time zone specification.
This is one of the following:
- The offset from
Coordinated Universal Time (‘
UTC
’)
specified as:
- [+-]hhmm
- [+-]hh:mm
- [+-]hh
- ‘
UTC
’
specified as:
- UTC
(‘
Coordinated Universal
time
’)
- GMT
(‘
Greenwich Mean Time
’)
- UT
(‘
Universal Time
’)
- Z
(‘
Zulu Time
’)
- A three character US time
zone specified as:
- EDT
- EST
- CDT
- CST
- MDT
- MST
- PDT
- PST
with the first letter standing for
‘Eastern
’ (“E”),
‘Central
’ (“C”),
‘Mountain
’ (“M”) or
‘Pacific
’ (“P”), and
the second letter standing for
‘Daylight
’ (“D” or
summer) time or ‘Standard
’
(“S”) time
- a single letter military
or nautical time zone specified as:
- “A”
through “I”
- “K”
through “Y”
- “J”
(non-nautical local time zone)
- An arbirtrary timezone
name that can be loaded from the database.
(A NetBSD extension.)
-
-
- %Z
- time zone name or no characters when time zone information
is unavailable. (A NetBSD extension.)
-
-
- %%
- matches a literal `%'. No argument is converted.
Modified conversion
specifications
For compatibility, certain conversion specifications 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 conversion specification. As there are
currently neither alternative formats nor specifications supported by the
system, the behavior will be as if the unmodified conversion specification
were used.
Case is ignored when matching string items in
buf, such as
month and weekday names.
RETURN VALUES
If successful, the
strptime() function returns a pointer to
the character following the last character parsed. Otherwise, a
NULL
pointer is returned.
SEE ALSO
ctime(3),
isspace(3),
localtime(3),
strftime(3),
tm(3)
STANDARDS
The
strptime() function conforms to
X/Open
Portability Guide Issue 4 (“XPG4”).
BUGS
The
%Z format specifier only accepts time zone abbreviations
of the local time zone, or the values “GMT” or “UTC”.
This limitation is caused by the ambiguity of overloaded time zone
abbreviations, for example EST is both Eastern Standard Time and Eastern
Australia Summer Time.