fscanf

StandardCLibrary

int fscanf( FILE *fp, char *fmt, ... )

FILE *fp; /* stream pointer */

char *fmt; /* format string */

Synopsis

#include "stdio.h"

The fscanf function reads from stream fp under control of format string fmt , and assigns converted values into subsequent arguments, each of which must be a pointer.

Parameters

fp is a stream pointer, open for input. fmt is a null-terminated string, containing format conversion specifications. Conversion specifiers take the following form:

%[flags][minimum field width][precision][size specification][conversion]

where:

flags	zero or more flag characters (-, +, 0, #, or space), (see below)
minimum field width	optional, a decimal constant, or *
precision	optional, a period optionally followed by a decimal constant
size specification	optional, one of l, L or h
conversion	one of c, d, e, E, f, g, G, i, n, o, p, s, u, x, X or % (see below)

Flags:

Flag	Meaning
-	left justify the value within field width
+	Always produce a sign, either + or -
0	Use 0 for pad character, not space
#	Use a variant conversion
space	Always produce either the sign - or a space

Conversion specifiers:

Char	Data type	Meaning
c	int	character conversion
d	int	signed decimal conversion
e	double	signed decimal floating point conversion
E	double	signed decimal floating point conversion
f	double	signed decimal floating point conversion
g	double	signed decimal floating point conversion
G	double	signed decimal floating point conversion
i	int	signed decimal conversion
n	int *	writes the number of characters output so far into an integer pointer
o	int	unsigned octal conversion
p	void *	pointer conversion
s	char *	string conversion
u	int	unsigned decimal conversion
x	int	unsigned hexadecimal conversion
X	int	unsigned hexadecimal conversion
%	none	a single percent sign is output

Return Value

fscanf returns EOF (-1) if end of file or error occurs before any conversion; otherwise it returns the number of items converted and assigned.