memchr(3) Library Functions Manual memchr(3)

memchr - memory search character

Standard C library (libc-lc)

#include <string.h>  // see memory.h(3head)
void *memchr(size_t n;
             const void s[n], int c, size_t n);

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.

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

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

Interface Attribute Value
memchr () Thread safety MT-Safe

C11, POSIX.1-2008.

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

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

2026-08-10 Linux man-pages 6.19