musl/src/stdio/__string_read.c

#include "stdio_impl.h"
#include <string.h>

size_t __string_read(FILE *f, unsigned char *buf, size_t len)
{
	char *src = f->cookie;
	size_t k = len+256;
	char *end = memchr(src, 0, k);
	if (end) k = end-src;
	if (k < len) len = k;
	memcpy(buf, src, len);
	f->rpos = (void *)(src+len);
	f->rend = (void *)(src+k);
	f->cookie = src+k;
	return len;
}
new scanf implementation and corresponding integer parser/converter advantages over the old code: - correct results for floating point (old code was bogus) - wide/regular scanf separated so scanf does not pull in wide code - well-defined behavior on integers that overflow dest type - support for %[a-b] ranges with %[ (impl-defined by widely used) - no intermediate conversion of fmt string to wide string - cleaner, easier to share code with strto* functions - better standards conformance for corner cases the old code remains in the source tree, as the wide versions of the scanf-family functions are still using it. it will be removed when no longer needed. 2012-04-16 16:03:45 -04:00			`#include "stdio_impl.h"`
clean up stdio_impl.h this header evolved to facilitate the extremely lazy practice of omitting explicit includes of the necessary headers in individual stdio source files; not only was this sloppy, but it also increased build time. now, stdio_impl.h is only including the headers it needs for its own use; any further headers needed by source files are included directly where needed. 2012-11-08 16:39:41 -05:00			`#include <string.h>`
new scanf implementation and corresponding integer parser/converter advantages over the old code: - correct results for floating point (old code was bogus) - wide/regular scanf separated so scanf does not pull in wide code - well-defined behavior on integers that overflow dest type - support for %[a-b] ranges with %[ (impl-defined by widely used) - no intermediate conversion of fmt string to wide string - cleaner, easier to share code with strto* functions - better standards conformance for corner cases the old code remains in the source tree, as the wide versions of the scanf-family functions are still using it. it will be removed when no longer needed. 2012-04-16 16:03:45 -04:00
			`size_t __string_read(FILE f, unsigned char buf, size_t len)`
			`{`
			`char *src = f->cookie;`
avoid depending on POSIX symbol in code used from plain C functions 2012-04-17 13:17:01 -04:00			`size_t k = len+256;`
			`char *end = memchr(src, 0, k);`
			`if (end) k = end-src;`
new scanf implementation and corresponding integer parser/converter advantages over the old code: - correct results for floating point (old code was bogus) - wide/regular scanf separated so scanf does not pull in wide code - well-defined behavior on integers that overflow dest type - support for %[a-b] ranges with %[ (impl-defined by widely used) - no intermediate conversion of fmt string to wide string - cleaner, easier to share code with strto* functions - better standards conformance for corner cases the old code remains in the source tree, as the wide versions of the scanf-family functions are still using it. it will be removed when no longer needed. 2012-04-16 16:03:45 -04:00			`if (k < len) len = k;`
			`memcpy(buf, src, len);`
			`f->rpos = (void *)(src+len);`
			`f->rend = (void *)(src+k);`
			`f->cookie = src+k;`
			`return len;`
			`}`