strftime.3

来自「<B>Digital的Unix操作系统VAX 4.2源码</B>」· 3 代码 · 共 122 行

.TH strftime 3
.SH Name
strftime \- convert time and date to string
.SH Syntax
.B #include <time.h>
.PP
.B int strftime (\fIs, maxsize, format, tm\fP)
.br
.B char *\fIs\fP;
.br
.B size_t \fImaxsize\fP;   
.br
.B char *\fIformat\fP;
.br
.B struct tm *\fItm\fP;
.SH Description
.NXR "strftime subroutine"
.PP
The
.PN strftime
function places characters in the array pointed to by \fIs\fR.
No more than \fImaxsize\fR characters are placed into the array.
The
.PN format
string controls this process.
This string consists of zero or more directives and ordinary characters.
A directive consists of a
.PN %
character followed by a character that determines the behavior of the 
directive.  All ordinary characters are copied unchanged into the array, 
including the terminating null character.
.PP
Each directive is replaced by the appropriate characters as shown in the 
following table. The characters are determined by the program's locale 
category
.PN LC_TIME
and the values contained in the structure pointed to by \fItm\fP.
.PP
.TS
tab(@);
lp-1v-1fHB lp-1v-1fHB
lp-1v-1 lp-1v-1.
.sp 6p
_
.sp 6p
Directive@Replaced by
.sp 6p
_
.sp 6p
%a@Locale's abbreviated weekday name
%A@Locale's full weekday name
%b@Locale's abbreviated month name
%B@Locale's full month name
%c@Locale's date and time representation
%d@Day of month as a decimal number (01\-31)
%D@Date (%m/%d/%y)
%h@Locale's abbreviated month name
%H@Hour as a decimal number (00\-23)
%I@Hour as a decimal number (01\-12)
%j@Day of year (001\-366)
%m@Number of month (01\-12)
%M@Minute number (00\-59)
%n@Newline character
%p@Locale's equivalent to AM or PM
%r@Time in AM/PM notation
%S@Second number (00\-59)
%t@Tab character
%T@Time (%H/%M/%S)
%U@Week number (00\-53), Sunday as first day of week
%w@Weekday number (0[Sunday]\-6)
%W@Week number (00\-53), Monday as first day of week
%x@Locale's date representation
%X@Locale's time representation
%y@Year without century (00\-99)
%Y@Year with century
%Z@Timezone name, no characters if no timezone
%%@%
.sp 6p
_
.TE
.PP
If a directive is used that is not contained in the table, 
the results are undefined.
.SS International Environment
.IP LC_TIME 15
Contains the user's requirements for language, territory, and codeset for
the time format. 
.PN LC_TIME 
affects the behavior of the time functions in
.PN strftime .
If
.PN LC_TIME
is not defined in the current environment, 
.PN LANG
provides the necessary default.
.IP LANG 15
If this environment is set and valid, 
.PN strftime
uses the international language database named in the definition to determine
the time formatting rules. If
.PN LC_TIME 
is defined, its definition supercedes the definition of 
.PN LANG .
.SH Return Values
If the total number of resulting characters, including the terminal null 
character, is not more than \fImaxsize\fR, the
.PN strftime
function returns the total of resultant characters placed into the 
array pointed to by \fIs\fR, not including the terminating null character.
In all other cases zero is returned and the contents of the array are 
indeterminate.
.PP
As the
.PN timezone
name is not contained in the \fItm\fR structure the value returned 
by \fI%Z\fR is determined by the
.PN timezone
function, see
.PN ctime .
.SH See Also
ctime(3), setlocale(3)