'\" t
.\" Copyright 1993, David Metcalfe <david@prism.demon.co.uk>
.\" Copyright, the authors of the Linux man-pages project
.\"
.\" SPDX-License-Identifier: Linux-man-pages-copyleft
.\"
.TH memchr 3 2026-08-10 "Linux man-pages 6.19"
.SH NAME
memchr \- memory search character
.SH LIBRARY
Standard C library
.RI ( libc ,\~ \-lc )
.SH SYNOPSIS
.nf
.BR #include\~<string.h> "  // see memory.h(3head)"
.P
.BR "void *memchr(" "size_t n;"
.BI "             const void " s [ n "], int " c ", size_t " n );
.fi
.SH DESCRIPTION
.BR memchr ()
scans the initial
.I n
bytes of the memory
area pointed to by
.I s
for the first instance of
.IR c .
.P
Both
.I c
and the bytes of the memory area pointed to by
.I s
are interpreted as
.IR "unsigned char" .
.SH RETURN VALUE
.BR memchr ()
returns a pointer to the matching byte
or NULL if the character does not occur in the given memory area.
.SH ATTRIBUTES
For an explanation of the terms used in this section, see
.BR attributes (7).
.TS
allbox;
lbx lb lb
l l l.
Interface	Attribute	Value
T{
.na
.nh
.BR memchr ()
T}	Thread safety	MT-Safe
.TE
.SH STANDARDS
C11, POSIX.1-2008.
.SH HISTORY
POSIX.1-2001, C89, SVr4, 4.3BSD.
.SH SEE ALSO
.BR memory.h (3head),
.BR memrchr (3),
.BR wmemchr (3)