NetBSD/lib/libc/time/strptime.3
tv 3c5e426d70 Fixes from PRs 5056 and 5161, partly rethought:
- %C and %y can be used in conjunction properly, though %y can have its
  old behaviour if used without %C
- %I formats hous 0..11 with 0 representing "12"; this is correct both
  with and without am/pm (%p rule fixed to compensate)
- %j fixed for range [0..365] in struct tm
- %m fixed for range [0..11] in struct tm
- %S fixed for range [0..61] in struct tm
1998-03-19 16:21:35 +00:00

184 lines
6.2 KiB
Groff

.\" $NetBSD: strptime.3,v 1.6 1998/03/19 16:21:35 tv Exp $
.\"
.\" Copyright (c) 1997, 1998 The NetBSD Foundation, Inc.
.\" All rights reserved.
.\"
.\" This file was contributed to The NetBSD Foundation by Klaus Klein.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\" notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\" notice, this list of conditions and the following disclaimer in the
.\" documentation and/or other materials provided with the distribution.
.\" 3. All advertising materials mentioning features or use of this software
.\" must display the following acknowledgement:
.\" This product includes software developed by the NetBSD
.\" Foundation, Inc. and its contributors.
.\" 4. Neither the name of The NetBSD Foundation nor the names of its
.\" contributors may be used to endorse or promote products derived
.\" from this software without specific prior written permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
.\" POSSIBILITY OF SUCH DAMAGE.
.\"
.Dd January 20, 1998
.Os
.Dt STRPTIME 3
.Sh NAME
.Nm strptime
.Nd converts a character string to a time value
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.Fd #include <time.h>
.Ft char *
.Fn strptime "const char *buf" "const char *format" "struct tm *tm"
.Sh DESCRIPTION
The
.Nm
function converts the character string pointed to by
.Fa buf
to values which are stored in the ``tm'' structure pointed to by
.Fa tm ,
using the format specified by
.Fa format .
.Pp
The
.Fa format
string consists of zero or more conversion specifications and
ordinary characters. All ordinary characters are copied directly into
the buffer. 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.
.Pp
The LC_TIME category defines the locale values for the conversion
specifications. The following conversion specifications are supported:
.Bl -tag -width "xxxx"
.It Cm \&%a
the day of week, using the locale's weekday names;
either the abbreviated or full name may be specified.
.It Cm \&%A
the same as
.Cm \&%a .
.It Cm \&%b
the month, using the locale's month names;
either the abbreviated or full name may be specified.
.It Cm \&%B
the same as
.Cm \&%b .
.It Cm \&%c
the date and time, using the locale's date and time format.
.It Cm \&%C
the century number [0,99];
leading zeros are permitted but not required. This conversion
should be used in conjunction with the \&%y conversion.
.It Cm \&%d
the day of month [1,31];
leading zeros are permitted but not required.
.It Cm \&%D
the date as %m/%d/%y.
.It Cm \&%e
the same as
.Cm \&%d .
.It Cm \&%h
the same as
.Cm \&%b .
.It Cm \&%H
the hour (24-hour clock) [0,23];
leading zeros are permitted but not required.
.It Cm \&%I
the hour (12-hour clock) [1,12];
leading zeros are permitted but not required.
.It Cm \&%j
the day number of the year [1,366];
leading zeros are permitted but not required.
.It Cm \&%k
the same as
.Cm \&%H .
.It Cm \&%l
the same as
.Cm \&%I .
.It Cm \&%m
the month number [1,12];
leading zeros are permitted but not required.
.It Cm \&%M
the minute [0,59];
leading zeros are permitted but not required.
.It Cm \&%n
any white-space
.It Cm \&%p
the locale's equivalent of a.m. or p.m..
.It Cm \&%r
the time (12-hour clock) with %p, using the locale's time format.
.It Cm \&%R
the time as %H:%M.
.It Cm \&%S
the seconds [0,61];
leading zeros are permitted but not required.
.It Cm \&%t
any white-space
.It Cm \&%T
the time as %H:%M:%S.
.It Cm \&%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.
.It Cm \&%w
the weekday as a decimal number [0,6], with 0 representing Sunday;
leading zeros are permitted but not required.
.It Cm \&%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.
.It Cm \&%x
the date, using the locale's date format.
.It Cm \&%X
the time, using the locale's time format.
.It Cm \&%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.
.It Cm \&%Y
the year, including the century (i.e., 1996).
.It Cm \&%%
A `%' is written. No argument is converted.
.El
.Ss Modified conversion specifications
For compatibility, certain conversion specifications can be modified
by the
.Cm E
and
.Cm 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.
.Sh RETURN VALUES
If successful, the
.Nm
function returns a pointer to the character following the last character
parsed. Otherwise, a null pointer is returned.
.Sh SEE ALSO
.Xr strftime 3
.Sh STANDARDS
The
.Fn strptime
function conforms to
.St -xpg4 .