gcc/libiberty/memchr.c

61 lines
1.2 KiB
C

/*
FUNCTION
<<memchr>>---find character in memory
INDEX
memchr
ANSI_SYNOPSIS
#include <string.h>
void *memchr(const void *<[src]>, int <[c]>, size_t <[length]>);
TRAD_SYNOPSIS
#include <string.h>
void *memchr(<[src]>, <[c]>, <[length]>)
void *<[src]>;
void *<[c]>;
size_t <[length]>;
DESCRIPTION
This function searches memory starting at <<*<[src]>>> for the
character <[c]>. The search only ends with the first
occurrence of <[c]>, or after <[length]> characters; in
particular, <<NULL>> does not terminate the search.
RETURNS
If the character <[c]> is found within <[length]> characters
of <<*<[src]>>>, a pointer to the character is returned. If
<[c]> is not found, then <<NULL>> is returned.
PORTABILITY
<<memchr>> requires no supporting OS subroutines.
QUICKREF
memchr ansi pure
*/
#include <ansidecl.h>
#ifdef __STDC__
#include <stddef.h>
#else
#define size_t unsigned long
#endif
PTR
memchr (src_void, c, length)
register const PTR src_void;
int c;
size_t length;
{
const unsigned char *src = (const unsigned char *)src_void;
while (--length >= 0)
{
if (*src == c)
return (PTR)src;
src++;
}
return NULL;
}