scanf_s.c File Reference

#include "safe_lib.h"

Include dependency graph for scanf_s.c:

Functions
EXPORT int	scanf_s (const char *restrict fmt,...)
	The scanf_s function reads a formatted string from stdin, and writes to a list of arguments.

Function Documentation

scanf_s()

EXPORT int scanf_s	(	const char *restrict	fmt,
			...
	)

The scanf_s function reads a formatted string from stdin, and writes to a list of arguments.

Reaching the end of the io buffer is equivalent to reaching the end-of-file condition for fscanf.

Remarks

SPECIFIED IN

• C11 standard (ISO/IEC 9899:2011): K.3.5.3.4 The scanf_s function (p: 594) http://en.cppreference.com/w/c/io/fscanf

Parameters

[in]	fmt	format-control string.
[out]	...	arguments to write to

Precondition

fmt shall be a null pointer.

fmt shall not contain the conversion specifier n

None of the arguments corresponding to s is a null pointer. (not yet)

No encoding error shall occur.

c, s, and %[ conversion specifiers each expect two arguments (the usual pointer and a value of type rsize_t indicating the size of the receiving array, which may be 1 when reading with a c into a single character) and except that the following errors are detected at runtime and call the currently installed constraint handler function. (not yet)

Warning

The current implementation just does some basic argument checks and then calls the native vsscanf() libc function. Thus the s null pointer check and the two-arg versions of c, s, and %[ are not yet implemented.

Returns

Number of receiving arguments successfully assigned, or EOF if read failure occurs before the first receiving argument was assigned or if there is a runtime constraint violation.

Return values

>	0 on success, the number of arguments assigned
EOF	on error

See also

vsscanf_s(), swscanf_s(), vsnprintf_s()