memchr(3) — Linux manual page

memchr(3)                Library Functions Manual               memchr(3)

NAME         top

       memchr - memory search character

LIBRARY         top

       Standard C library (libc, -lc)

SYNOPSIS         top

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

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

DESCRIPTION         top

       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         top

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

ATTRIBUTES         top

       For an explanation of the terms used in this section, see
       attributes(7).
       ┌──────────────────────────────────────┬───────────────┬─────────┐
       │ Interface                            │ Attribute     │ Value   │
       ├──────────────────────────────────────┼───────────────┼─────────┤
       │ memchr()                             │ Thread safety │ MT-Safe │
       └──────────────────────────────────────┴───────────────┴─────────┘

STANDARDS         top

       C11, POSIX.1-2008.

HISTORY         top

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

SEE ALSO         top

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

COLOPHON         top

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

Pages that refer to this page: ffs(3),  memory.h(3head),  memrchr(3),  rawmemchr(3),  strchr(3),  wmemchr(3),  signal-safety(7)

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