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'\" t
.\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk)
.\"
.\" SPDX-License-Identifier: Linux-man-pages-copyleft
.\"
.\" References consulted:
.\" Linux libc source code
.\" Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991)
.\" 386BSD man pages
.\" Modified Sat Jul 24 18:54:45 1993 by Rik Faith (faith@cs.unc.edu)
.TH memfrob 3 2022-12-15 "Linux man-pages 6.03"
.SH NAME
memfrob \- frobnicate (obfuscate) a memory area
.SH LIBRARY
Standard C library
.RI ( libc ", " \-lc )
.SH SYNOPSIS
.nf
.BR "#define _GNU_SOURCE" " /* See feature_test_macros(7) */"
.B #include <string.h>
.PP
.BI "void *memfrob(void " s [. n "], size_t " n );
.fi
.SH DESCRIPTION
The
.BR memfrob ()
function obfuscates the first \fIn\fP bytes of the
memory area \fIs\fP by exclusive-ORing each character with the number
42.
The effect can be reversed by using
.BR memfrob ()
on the
obfuscated memory area.
.PP
Note that this function is not a proper encryption routine as the XOR
constant is fixed, and is suitable only for hiding strings.
.SH RETURN VALUE
The
.BR memfrob ()
function returns a pointer to the obfuscated memory
area.
.SH ATTRIBUTES
For an explanation of the terms used in this section, see
.BR attributes (7).
.ad l
.nh
.TS
allbox;
lbx lb lb
l l l.
Interface Attribute Value
T{
.BR memfrob ()
T} Thread safety MT-Safe
.TE
.hy
.ad
.sp 1
.SH STANDARDS
The
.BR memfrob ()
function is unique to the
GNU C Library.
.SH SEE ALSO
.BR bstring (3),
.BR strfry (3)
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