NAME

vfscanf, vscanf, vsscanf — format input of a stdarg argument list

SYNOPSIS

#include <stdarg.h>
#include <stdio.h>

int vfscanf(FILE *restrict stream, const char *restrict format,
       va_list arg);
int vscanf(const char *restrict format, va_list arg);
int vsscanf(const char *restrict s, const char *restrict format,
       va_list arg);


DESCRIPTION

^[CX] The functionality described on this reference page is aligned with the ISO C standard. Any conflict between the requirements described here and the ISO C standard is unintentional. This volume of POSIX.1-2024 defers to the ISO C standard.

The vscanf(), vfscanf(), and vsscanf() functions shall be equivalent to the scanf(), fscanf(), and sscanf() functions, respectively, except that instead of being called with a variable number of arguments, they are called with an argument list as defined in the <stdarg.h> header. These functions shall not invoke the va_end macro. As these functions invoke the va_arg macro, the value of ap after the return is unspecified.

RETURN VALUE

Refer to fscanf.

ERRORS

Refer to fscanf.

EXAMPLES

None.

APPLICATION USAGE

Applications using these functions should call va_end(ap) afterwards to clean up.

RATIONALE

None.

FUTURE DIRECTIONS

None.

SEE ALSO

2.5 Standard I/O Streams, fscanf

XBD <stdarg.h>, <stdio.h>

CHANGE HISTORY

First released in Issue 6. Derived from the ISO/IEC 9899:1999 standard.

Issue 7

POSIX.1-2008, Technical Corrigendum 1, XSH/TC1-2008/0704 [14] is applied.