memchr, memrchr, rawmemchr - scan memory for a character
#include <string.h> void *memchr(const void *s, int c, size_t n); void *memrchr(const void *s, int c, size_t n); void *rawmemchr(const void *s, int c);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
The memchr() function scans the initial
n bytes of the memory area pointed to by
s for the first instance of
c and the bytes of the memory area pointed to by
s are interpreted as
The rawmemchr() function is similar to memchr(): it assumes (i.e., the programmer knows for certain) that an instance of
c lies somewhere in the memory area starting at the location pointed to by
s, and so performs an optimized search for
c (i.e., no use of a count argument to limit the range of the search). If an instance of
c is not found, the results are unpredictable. The following call is a fast means of locating a string's terminating null byte:
char *p = rawmemchr(s, '\0');
The rawmemchr() function returns a pointer to the matching byte, if one is found. If no matching byte is found, the result is unspecified.
rawmemchr() first appeared in glibc in version 2.1.
memrchr() first appeared in glibc in version 2.2.
For an explanation of the terms used in this section, see attributes(7).
|memchr(), memrchr(), rawmemchr()||Thread safety||MT-Safe|
memchr(): POSIX.1-2001, POSIX.1-2008, C89, C99, SVr4, 4.3BSD.
The memrchr() function is a GNU extension, available since glibc 2.1.91.
The rawmemchr() function is a GNU extension, available since glibc 2.1.
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