+++ /dev/null
-.\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk)
-.\"
-.\" %%%LICENSE_START(VERBATIM)
-.\" Permission is granted to make and distribute verbatim copies of this
-.\" manual provided the copyright notice and this permission notice are
-.\" preserved on all copies.
-.\"
-.\" Permission is granted to copy and distribute modified versions of this
-.\" manual under the conditions for verbatim copying, provided that the
-.\" entire resulting derived work is distributed under the terms of a
-.\" permission notice identical to this one.
-.\"
-.\" Since the Linux kernel and libraries are constantly changing, this
-.\" manual page may be incorrect or out-of-date. The author(s) assume no
-.\" responsibility for errors or omissions, or for damages resulting from
-.\" the use of the information contained herein. The author(s) may not
-.\" have taken the same level of care in the production of this manual,
-.\" which is licensed free of charge, as they might when working
-.\" professionally.
-.\"
-.\" Formatted or processed versions of this manual, if unaccompanied by
-.\" the source, must acknowledge the copyright and authors of this work.
-.\" %%%LICENSE_END
-.\"
-.\" References consulted:
-.\" Linux libc source code
-.\" Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991)
-.\" 386BSD man pages
-.\" Modified Sat Jul 24 18:55:27 1993 by Rik Faith (faith@cs.unc.edu)
-.TH MEMCMP 3 2014-12-31 "" "Linux Programmer's Manual"
-.SH NAME
-memcmp \- compare memory areas
-.SH SYNOPSIS
-.nf
-.B #include <string.h>
-.sp
-.BI "int memcmp(const void *" s1 ", const void *" s2 ", size_t " n );
-.fi
-.SH DESCRIPTION
-The
-.BR memcmp ()
-function compares the first \fIn\fP bytes (each interpreted as
-.IR "unsigned char" )
-of the memory areas \fIs1\fP and \fIs2\fP.
-.SH RETURN VALUE
-The
-.BR memcmp ()
-function returns an integer less than, equal to, or
-greater than zero if the first \fIn\fP bytes of \fIs1\fP is found,
-respectively, to be less than, to match, or be greater than the first
-\fIn\fP bytes of \fIs2\fP.
-
-For a nonzero return value, the sign is determined by the sign of
-the difference between the first pair of bytes (interpreted as
-.IR "unsigned char" )
-that differ in
-.I s1
-and
-.IR s2 .
-
-If
-.I n
-is zero, the return value is zero.
-.SH ATTRIBUTES
-.SS Multithreading (see pthreads(7))
-The
-.BR memcmp ()
-function is thread-safe.
-.SH CONFORMING TO
-SVr4, 4.3BSD, C89, C99, POSIX.1-2001.
-.SH NOTES
-.PP
-Do not use
-.BR memcmp ()
-to compare security critical data, such as cryptographic secrets,
-because the required CPU time depends on the number of equal bytes.
-Instead, a function that performs comparisons in constant time is required.
-Some operating systems provide such a function (e.g., NetBSD's
-.BR consttime_memequal ()),
-but no such function is specified in POSIX.
-On Linux, it may be necessary to implement such a function oneself.
-.SH SEE ALSO
-.BR bcmp (3),
-.BR strcasecmp (3),
-.BR strcmp (3),
-.BR strcoll (3),
-.BR strncasecmp (3),
-.BR strncmp (3),
-.BR wmemcmp (3)
-.SH COLOPHON
-This page is part of release 3.79 of the Linux
-.I man-pages
-project.
-A description of the project,
-information about reporting bugs,
-and the latest version of this page,
-can be found at
-\%http://www.kernel.org/doc/man\-pages/.
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