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.
vfscanf, vscanf, vsscanf — format input of a stdarg argument list
int vfscanf(FILE *restrict stream, const char *restrict format,
int vscanf(const char *restrict format, va_list arg);
int vsscanf(const char *restrict s, const char *restrict format,
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.
Refer to fscanf().
The following sections are informative.
Applications using these functions should call va_end(ap)
afterwards to clean up.
Section 2.5, Standard I/O Streams, fscanf()
The Base Definitions volume of POSIX.1‐2017,
Portions of this text are reprinted and reproduced in electronic form from IEEE
Std 1003.1-2017, Standard for Information Technology -- Portable Operating
System Interface (POSIX), The Open Group Base Specifications Issue 7, 2018
Edition, Copyright (C) 2018 by the Institute of Electrical and Electronics
Engineers, Inc and The Open Group. In the event of any discrepancy between
this version and the original IEEE and The Open Group Standard, the original
IEEE and The Open Group Standard is the referee document. The original
Standard can be obtained online at http://www.opengroup.org/unix/online.html .
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