NAME

       memchr, memrchr, rawmemchr - scan memory for a character

LIBRARY

       Standard C library (libc, -lc)

SYNOPSIS

       #include <string.h>

       void *memchr(const void s[.n], int c, size_t n);
       void *memrchr(const void s[.n], int c, size_t n);

       [[deprecated]] void *rawmemchr(const void s[.n], int c);

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       memrchr(), rawmemchr():
           _GNU_SOURCE

DESCRIPTION

       The memchr() function scans the initial n bytes of the memory area pointed to by s for the
       first instance of c.  Both c and the bytes  of  the  memory  area  pointed  to  by  s  are
       interpreted as unsigned char.

       The  memrchr()  function  is  like the memchr() function, except that it searches backward
       from the end of the n bytes pointed to by s instead of forward from the beginning.

       The rawmemchr() function is similar to memchr(), but  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.  If an instance of c is not found, the  behavior  is  undefined.
       Use either strlen(3) or memchr(3) instead.

RETURN VALUE

       The  memchr() and memrchr() functions return a pointer to the matching byte or NULL if the
       character does not occur in the given memory area.

       The rawmemchr() function returns a pointer to the matching byte.

VERSIONS

       rawmemchr() first appeared in glibc 2.1.

       memrchr() first appeared in glibc 2.2.

ATTRIBUTES

       For an explanation of the terms used in this section, see attributes(7).

       ┌───────────────────────────────────────────────────────────────┬───────────────┬─────────┐
       │Interface                                                      │ Attribute     │ Value   │
       ├───────────────────────────────────────────────────────────────┼───────────────┼─────────┤
       │memchr(), memrchr(), rawmemchr()                               │ Thread safety │ MT-Safe │
       └───────────────────────────────────────────────────────────────┴───────────────┴─────────┘

STANDARDS

       memchr(): POSIX.1-2001, POSIX.1-2008, 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.

SEE ALSO

       bstring(3), ffs(3), memmem(3), strchr(3), strpbrk(3),  strrchr(3),  strsep(3),  strspn(3),
       strstr(3), wmemchr(3)