u8sscanf_s.c File Reference

#include "safe_u8_lib.h"

Include dependency graph for u8sscanf_s.c:

Functions
EXPORT int	u8sscanf_s (const char8_t *restrict buffer, const char *restrict fmt,...)
	The u8sscanf_s function reads a formatted utf-8 string, and writes to a list of arguments.

Function Documentation

u8sscanf_s()

EXPORT int u8sscanf_s	(	const char8_t *restrict	buffer,
		const char *restrict	fmt,
			... )

The u8sscanf_s function reads a formatted utf-8 string, and writes to a list of arguments.

UTF-8 is byte-compatible with the underlying scanner, so this is otherwise identical to sscanf_s(), except that – unlike the rest of the scanf_s family – the c, s, and %[ conversion specifiers here require their Annex K companion rsize_t destination- size argument: u8sscanf_s() always consumes and enforces it, since it has the whole source buffer available up front to do so safely (unlike the streaming scanf_s variants, where that two-argument convention is documented but not yet enforced).

Parameters

[in]	buffer	pointer to a NUL-terminated utf-8 string to read from
[in]	fmt	format-control string.
[out]	...	arguments to write to; every c, s, and %[ is followed by an rsize_t giving the size of its destination array

Precondition

Neither buffer nor fmt shall be a null pointer.

buffer shall not contain an illegal or truncated UTF-8 sequence.

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).

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, or when buffer contains illegal UTF-8 or a c/s/%[ destination is too small (errno set to EILSEQ resp. ESNOSPC)

See also

vu8sscanf_s(), sscanf_s()