vprintf(3int)vprintf(3int)Name
vprintf, vfprintf, vsprintf - print formatted output of a varargs argu‐
ment list
Syntax
#include <stdio.h>
#include <varargs.h>
int vprintf ( format, ap )
char *format;
va list ap;
int vfprintf ( stream, format, ap )
FILE *stream;
char *format;
va list ap;
int vsprintf ( s, format, ap )
char *s, *format;
va list ap;
Description
The international functions and are similar to the standard I/O func‐
tions.
Likewise, the vprintf functions are similar to the printf functions
except they are called with an argument list as defined by instead of
with a variable number of arguments.
The international functions allow you to use the %digit$ conversion
character in place of the % character you use in the standard I/O
functions. The digit is a decimal digit n from 1 to 9. The interna‐
tional functions apply conversions to the nth argument in the argument
list, rather than to the next unused argument.
You can use the % conversion character in the international functions.
However, you cannot mix the % conversion character with the %digit$
conversion character in a single call.
You can indicate a field width or precision by an asterisk (*) instead
of a digit string in format strings containing the % conversion charac‐
ter. If you use an asterisk, you can supply an integer arg that speci‐
fies the field width or precision. In format strings containing the
%digit$ conversion character, you can indicate field width or precision
by the sequence *digit$. You use a decimal digit from 1 to 9 to indi‐
cate which argument contains an integer that specifies the field width
or precision.
The conversion characters and their meanings are identical to
You must use each digit argument at least once.
Examples
#include <stdio.h>
#include <varargs.h>
main()
{
char *function_name = "vpr";
char *arg1 = "hello world";
int arg2 = 2;
char *arg3 = "study";
char *i18nfmt = "%1$s %3$d\n";
test(function_name, i18nfmt, arg1, arg2, arg3);
}
test(va_alist)
va_dcl
{
va_list args;
char *fmt;
char string[1024];
va_start(args);
(void)printf("function %s: ", va_arg(args, char *));
fmt = va_arg(args, char *);
(void)vprintf(fmt, args);
va_end(args);
}
See Alsosetlocale(3), scanf(3int), printf(3s), printf(3int), vprintf(3s),
putc(3s), scanf(3s), stdio(3s), varargs(3)
Guide to Developing International Software
vprintf(3int)
