#!/bin/sh
# This is a shar archive.
# The rest of this file is a shell script which will extract:
#
# 4_11.c 4_11.cmp 4_11.in 4_11b.c makefile
#
# To extract the files from this shell archive file simply
# create a directory for this file, move the archive file
# to it and enter the command
#
#	sh filename
# 
# The files will be extracted automatically.
# Note: Do not use csh.
#
# Archive created: Mon Jul 30 23:00:00 EDT 1990
#
echo x - 4_11.c
sed 's/^X//' > 4_11.c << '!EOF!'
/* Copyright (c) 1990 by AT&T Bell Telephone Laboratories, Incorporated. */
/* The C++ Answer Book */
/* Tony Hansen */
/* All rights reserved. */
// Encrypt input with provided key
// using simple XOR algorithm.
// No key or NULL key gives cleartext.
#include <stream.h>
#include <string.h>
#include <error.h>

int main(int argc, char **argv)
{
    char c;

    switch (argc)
	{
	case 1:		// no key: cleartext copy
	    while (cin.get(c) && cout.put(c))
		;
	    break;

	case 2:		// provided key: encrypted copy
	    char *key = argv[1];
	    int codelen = strlen(key);
	    int i = 0;

	    while (cin.get(c) && cout.put(c ^ key[i++]))
		i %= codelen;
	    break;

	default:	// usage error
	    cerr << "usage: " << argv[0] <<
		" [key] < clear > crypt\n";
	    return 1;
	}

    if (cout.bad())
	error("output failed");

    else if (!cin.eof())
	error("input failed");

    return 0;
}
!EOF!
ls -l 4_11.c
echo x - 4_11.cmp
sed 's/^X//' > 4_11.cmp << '!EOF!'

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!EOF!
ls -l 4_11.cmp
echo x - 4_11.in
sed 's/^X//' > 4_11.in << '!EOF!'
root::0:root
other::1:
bin::2:root,bin,daemon
sys::3:root,bin,sys,adm
adm::4:root,adm,daemon
uucp::5:root,uucp
mail::6:root
daemon::12:root,daemon
docx::21:pcor,russak,mds,dsl,jeremy,bwp,hansen,coleman,chu,jack
guest::22:
cmts::23:cmts,hansen,mzal
mesa::24:mesa,hansen,mzal
mrstat::26:cmts,hansen,mzal,bwp,danb,guidi,linda,dsl,eby,cbp,hlb,pcor,russak,clt,mds,aku,wpw,jack,cjs,bcc,paul,alf,sld,drr,jim,larry,jmt
intest::27:
arch::29:efh,maryrose,danb,russak,linda
ots::31:butterly,fwl,daved,so,dwr,shorty,mjk,mjm,aj
dbx::35:
erm::37:efs,caf,jaa,mjb,lth,rlm
games::50:hansen,autilio,avi
news::51:netnews
slan::57:slan,root
sie::80:
sable::117:sable
dptg::88:emm,kbs,jak,ecc,jhc,jrw,rkh
DOS-ash::92:msnet
DOS--sh::93:msnet
DOS-a-h::94:msnet
DOS-as-::95:msnet
DOS---h::96:msnet
DOS--s-::97:msnet
DOS-a--::98:msnet
DOS----::99:msnet
exptools::90:exptools
vm::100:vmsys
pcor::102:pcor,russak,eth,jim,hansen,jack
dx::880:
OLD::1000:scy
olympus::1100:olympus,aku
tsys::1101:root,tadm
!EOF!
ls -l 4_11.in
echo x - 4_11b.c
sed 's/^X//' > 4_11b.c << '!EOF!'
/* Copyright (c) 1990 by AT&T Bell Telephone Laboratories, Incorporated. */
/* The C++ Answer Book */
/* Tony Hansen */
/* All rights reserved. */
// Encrypt input with provided key
// using simple XOR algorithm.
// No key or NULL key gives cleartext.
// stdio version
#include <stdio.h>
#include <string.h>
#include <error.h>

int main(int argc, char **argv)
{
    int c;

    switch (argc)
	{
	case 1:		// no key: cleartext copy
	    while (((c = getchar()) != EOF) &&
		   (putchar(c) != EOF))
		;
	    break;

	case 2:		// provided key: encrypted copy
	    char *key = argv[1];
	    int codelen = strlen(key);
	    int i = 0;

	    while (((c = getchar()) != EOF) &&
		   (putchar(c ^ key[i++]) != EOF))
		i %= codelen;
	    break;

	default:	// usage error
	    (void) fprintf(stderr,
		"usage: %s [key] < clear > crypt\n",
		argv[0]);
	    return 1;
	}

    if (ferror(stdout))
	error("output failed");

    else if (!feof(stdin))
	error("input failed");

    return 0;
}
!EOF!
ls -l 4_11b.c
echo x - makefile
sed 's/^X//' > makefile << '!EOF!'
CC= CC -I. -I../../CC
ERROR=  ../../error.o
CFLAGS= +i -g

all: 4_11 4_11b

4_11: 4_11.c
	$(CC) $(CFLAGS) 4_11.c -o 4_11 $(ERROR)

4_11b: 4_11b.c
	$(CC) $(CFLAGS) 4_11b.c -o 4_11b $(ERROR)

OUT= 4_11a1.out 4_11a2.out 4_11b1.out 4_11a3.out 4_11a4.out 4_11b2.out
CMP= 4_11.cmp 4_11.in

4_11a1.out: 4_11 4_11.in ;	4_11 < 4_11.in > 4_11a1.out
4_11a2.out: 4_11 4_11.in ;	4_11 testing123 < 4_11.in > 4_11a2.out
4_11b1.out: 4_11 4_11a1.out ;	4_11 testing123 < 4_11a1.out > 4_11b1.out
4_11a3.out: 4_11b 4_11.in ;	4_11b < 4_11.in > 4_11a3.out
4_11a4.out: 4_11b 4_11.in ;	4_11b testing123 < 4_11.in > 4_11a4.out
4_11b2.out: 4_11b 4_11a4.out ;	4_11b testing123 < 4_11a4.out > 4_11b2.out

test: all $(OUT) $(CMP)
	cmp 4_11a1.out 4_11.in
	cmp 4_11a2.out 4_11.cmp
	cmp 4_11b1.out 4_11.in
	cmp 4_11a3.out 4_11.in
	cmp 4_11a4.out 4_11.cmp
	cmp 4_11b2.out 4_11.in
	echo tests done
!EOF!
ls -l makefile
# The following exit is to ensure that extra garbage 
# after the end of the shar file will be ignored.
exit 0