vfscanf
Scans and formats input from a stream.
Defined in header <stdio.h>
Syntax
#include <stdio.h>
int vfscanf(FILE *stream, const char *format, vajist arglist);Portability
| DOS | UNIX | Windows | ANSI C | C++ only |
|---|---|---|---|---|
| ■ | ■ | ■ |
Remarks
Available on UNIX System V.
The v...scanf functions are known as alternate entry points for the ...scant functions. They behave exactly like their ...scant counterparts, but they accept a pointer to a list of arguments instead of an argument list.
See scant for details
vtscanf scans a series of input fields, one character at a time,
on format specifiers.
| from a stream. Then each field is formatted | to |
| reading format specifier passed to vfscanf in the format string pointed to by format. Finally, vfscanf stores the formatted input at an address passed to it as an argument following/ormaf. There must be the same number of format specifiers and addresses as there are input fields. | according a |
vfscanf might stop scanning a particular field before it reaches the normal end-of-field (whitespace) character, or it might terminate entirely, for a number of reasons. See scant for a discussion of possible causes.
Return value
vtscanf returns the number of input fields successfully scanned, converted, and stored; the return value does not include scanned fields that were not stored. If no fields were stored, the return value is 0.
If vtscanf attempts to read at end-of-file, the return value is EOF.
See also
Example
#include <stdio.h>
#include <stdlib.h>
FILE *fp;
int vfsf (char *fmt, ...)
{
va_list argptr;
int cnt;
va_start (argptr, fmt);
cnt = vfscanf (fp, fmt, argptr);
va_end (argptr);
return (cnt);
}
int main (void)
{
int inumber = 30;
float fnumber = 90.0;
char string [4] = "abc";
fp = tmpfileO ;
if (fp == NULL) {
perror( "tmpfileO call");
exit(l);
}
fprintf (fp,"%d %f %s\n",inumber,fnumber, string)
rewind (fp);
vfsf("%d %f %s",&inumber,&fnumber, string);
printf("%d %f %s\n",inumber,fnumber, string);
fclose (fp);
return 0;Differences from modern implementations
Nothing recorded yet.
Modern references
These are search links, not yet checked by hand.
Stable link: /3.1/stdio.h/vfscanf/
· short form /3.1/vfscanf/