vsnprint.gml

开放源码的编译器open watcom 1.6.0版的源代码

.func vsnprintf vsnwprintf
.funcw vsnwprintf
#include <stdarg.h>
#include <stdio.h>
int vsnprintf( char *buf,
               size_t count,
               const char *format,
               va_list arg );
.ixfunc2 '&String' &func
.if &'length(&wfunc.) ne 0 .do begin
#include <stdarg.h>
#include <wchar.h>
int vsnwprintf( wchar_t *buf,
                size_t count,
                const wchar_t *format,
                va_list arg );
.ixfunc2 '&String' &wfunc
.ixfunc2 '&Wide' &wfunc
.do end
.funcend
.*
.safealt
.*
.desc begin
The &func function formats data under control of the
.arg format
control string and stores the result in
.arg buf.
The maximum number of characters to store, including a terminating
null character, is specified by
.arg count.
The
.arg format
string is described under the description of the
.kw printf
function.
The &func function is equivalent to the
.kw _snprintf
function, with the variable argument list replaced with
.arg arg,
which has been initialized by the
.kw va_start
macro.
.if &'length(&wfunc.) ne 0 .do begin
.np
The &wfunc function is identical to &func except that the argument
.arg buf
specifies an array of wide characters into which the generated output
is to be written, rather than converted to multibyte characters and
written to a stream.
The maximum number of wide characters to write, including a
terminating null wide character, is specified by
.arg count.
The &wfunc function accepts a wide-character string argument for
.arg format
.do end
.desc end
.*
.return begin
The &func function returns the number of characters that would have been
written had
.arg count
been sufficiently large, not counting the terminating null
character, or a negative value if an encoding error occurred.
Thus, the null-terminated output has been completely written if and only
if the returned value is nonnegative and less than
.arg count.
.if &'length(&wfunc.) ne 0 .do begin
The &wfunc function returns the number of wide characters that would have
been written had
.arg count
been sufficiently large, not counting the terminating null wide character,
or a negative value if an encoding error occurred.
Thus, the null-terminated output has been completely written if and only
if the returned value is nonnegative and less than
.arg count.
.do end
.im errnoref
.return end
.*
.see begin
.im seevprtf vsnprintf
.see end
.*
.exmp begin
.blktext begin
The following shows the use of &func in a general error message routine.
.blktext end
.blkcode begin
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>

char *fmtmsg( char *format, ... )
{
    char    *msgbuf;
    int     len;
    va_list arglist;

    va_start( arglist, format );
    len = vsnprintf( NULL, 0, format, arglist );
    va_end( arglist );
    len = len + 1 + 7;
    msgbuf = malloc( len );
    strcpy( msgbuf, "Error: " );
    va_start( arglist, format );
    vsnprintf( &msgbuf[7], len, format, arglist );
    va_end( arglist );
    return( msgbuf );
}

void main( void )
{
    char *msg;

    msg = fmtmsg( "%s %d %s", "Failed", 100, "times" );
    printf( "%s\n", msg );
    free( msg );
}
.blkcode end
.exmp end
.*
.class ANSI
.system