memchr(3)                  Library Functions Manual                  memchr(3)

NAME
       memchr - memory search character

LIBRARY
       Standard C library (libc, -lc)

SYNOPSIS
       #include <string.h>  // see memory.h(3head)

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

DESCRIPTION
       memchr() 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.

RETURN VALUE
       memchr() returns a pointer to the matching byte or NULL if the
       character does not occur in the given memory area.

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

       +--------------------------------------------+---------------+---------+
       |Interface                                   | Attribute     | Value   |
       +--------------------------------------------+---------------+---------+
       |memchr ()                                   | Thread safety | MT-Safe |
       +--------------------------------------------+---------------+---------+
STANDARDS
       C11, POSIX.1-2008.

HISTORY
       POSIX.1-2001, C89, SVr4, 4.3BSD.

SEE ALSO
       memory.h(3head), memrchr(3), wmemchr(3)

Linux man-pages 6.19              2026-08-10                         memchr(3)