vfscanf3p
Format input of a stdarg argument list
Usage
#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);
Prolog
This manual page is part of the POSIX Programmer's Manual. The Linux implementation of this interface may differ (consult the corresponding Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux.
Overview
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.1‐2017 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().
The following sections are informative.
Examples
None.
Application usage
Applications using these functions should call va_end( ap) afterwards to clean up.
Rationale
None.
Future directions
None.