| Standards / Extensions | C or C++ | Dependencies |
|---|---|---|
C99 |
both | z/OS® V1R7 |
#define _ISOC99_SOURCE
#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);
#define _OPEN_SYS_UNLOCKED_EXT 1
#include <stdio.h>
int vfscanf_unlocked(FILE *__restrict__ stream,
const char *__restrict__ format, va_list arg);
int vscanf_unlocked(const char *__restrict__ format, va_list arg);The vfscanf(), vscanf(), and vsscanf() functions are equivalent to the fscanf(), scanf(), 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 stdarg.h.
The argument list should be initialized using the va_start macro before each call. These functions do not invoke the va_end macro, but instead invoke the va_arg macro causing the value of arg after the return to be unspecified.
vfscanf() and vscanf() are not supported for files opened with a record type. They also have the same restrictions as a write immediately following a read or a read immediately following a write. This is because, between a write and a subsequent read, there must be an intervening flush or reposition and between a read and a subsequent write, there must also be an intervening flush or reposition unless EOF has been reached.
vfscanf_unlocked() and vscanf_unlocked() are functionally equivalent to vfscanf() and vscanf() with the exception that they are not thread-safe. These functions may safely be used in a multithreaded application if and only they are called while the invoking thread owns the (FILE*) object, as is the case after a successful call to either the flockfile() or ftrylockfile() function.
Refer to fscanf().