freebsd-dev/lib/libc/string/memchr.3

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.\"     @(#)memchr.3	8.1 (Berkeley) 6/4/93
.\" $FreeBSD$
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.Dd April 9, 2008
.Dt MEMCHR 3
.Os
.Sh NAME
.Nm memchr
.Nd locate byte in byte string
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In string.h
.Ft void *
.Fn memchr "const void *b" "int c" "size_t len"
.Ft void *
.Fn memrchr "const void *b" "int c" "size_t len"
.Sh DESCRIPTION
The
.Fn memchr
function
locates the first occurrence of
.Fa c
(converted to an unsigned char)
in string
.Fa b .
.Pp
The
.Fn memrchr
function behaves like
.Fn memchr ,
except that it locates the last occurrence of
.Fa c
in string
.Fa b .
.Sh RETURN VALUES
The
.Fn memchr
and
.Fn memrchr
functions
return a pointer to the byte located,
or NULL if no such byte exists within
.Fa len
bytes.
.Sh SEE ALSO
.Xr memmem 3 ,
.Xr strchr 3 ,
.Xr strcspn 3 ,
.Xr strpbrk 3 ,
.Xr strrchr 3 ,
.Xr strsep 3 ,
.Xr strspn 3 ,
.Xr strstr 3 ,
.Xr strtok 3 ,
.Xr wmemchr 3
.Sh STANDARDS
The
.Fn memchr
function
conforms to
.St -isoC .
.Pp
The
.Fn memrchr       
function is a GNU extension and conforms to no standard.
.Sh HISTORY
The
.Fn memrchr
function first appeared in GNU libc 2.1.91, this implementation
first appeared in
.Fx 8.0 ,
coming from
.Ox 4.3 .