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.Dd August 18, 2002
.Os
.Dt STRPTIME 3
.Sh NAME
.Nm strptime
.Nd converts a character string to a time value
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In time.h
.Ft char *
.Fn strptime "const char * restrict buf" "const char * restrict format" "struct tm * restrict tm"
.Sh DESCRIPTION
The
.Fn strptime
function converts the character string pointed to by
.Fa buf
to values which are stored in the
.Va 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, whitespace
characters as defined by
.Fn isspace ,
and ordinary characters.
All ordinary characters in
.Fa format
are compared directly against the corresponding characters in
.Fa buf ;
comparisons which fail will cause
.Fn strptime
to fail.
Whitespace characters in
.Fa format
match any number of whitespace characters in
.Fa buf ,
including none.
.Pp
A conversion specification consists of a percent sign
.Ql %
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
Conversion of alphanumeric strings (such as month and weekday names) is
done without regard to case.
Conversion specifications which cannot be matched will cause
.Fn strptime
to fail.
.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, including none.
.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, including none.
.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.
.Pp
Case is ignored when matching string items in
.Fa buf ,
such as month and weekday names.
.Sh RETURN VALUES
If successful, the
.Fn strptime
function returns a pointer to the character following the last character
parsed.
Otherwise, a null pointer is returned.
.Sh SEE ALSO
.Xr ctime 3 ,
.Xr isspace 3 ,
.Xr localtime 3 ,
.Xr strftime 3
.Sh STANDARDS
The
.Fn strptime
function conforms to
.St -xpg4 .