unvis.c revision 72445 
1/*	$NetBSD: unvis.c,v 1.19 2000/01/22 22:19:13 mycroft Exp $	*/
2
3/*-
4 * Copyright (c) 1989, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. All advertising materials mentioning features or use of this software
16 *    must display the following acknowledgement:
17 *	This product includes software developed by the University of
18 *	California, Berkeley and its contributors.
19 * 4. Neither the name of the University nor the names of its contributors
20 *    may be used to endorse or promote products derived from this software
21 *    without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36#if 1
37#ifdef HAVE_CONFIG_H
38#include <config.h>
39RCSID("$Id: unvis.c,v 1.2 2000/12/06 21:41:46 joda Exp $");
40#endif
41#include <roken.h>
42#ifndef _DIAGASSERT
43#define _DIAGASSERT(X)
44#endif
45#else
46#include <sys/cdefs.h>
47#if defined(LIBC_SCCS) && !defined(lint)
48#if 0
49static char sccsid[] = "@(#)unvis.c	8.1 (Berkeley) 6/4/93";
50#else
51__RCSID("$NetBSD: unvis.c,v 1.19 2000/01/22 22:19:13 mycroft Exp $");
52#endif
53#endif /* LIBC_SCCS and not lint */
54
55#define __LIBC12_SOURCE__
56
57#include "namespace.h"
58#endif
59#include <sys/types.h>
60
61#include <assert.h>
62#include <ctype.h>
63#include <stdio.h>
64#include <vis.h>
65
66#if 0
67#ifdef __weak_alias
68__weak_alias(strunvis,_strunvis)
69__weak_alias(unvis,_unvis)
70#endif
71
72__warn_references(unvis,
73    "warning: reference to compatibility unvis(); include <vis.h> for correct reference")
74#endif
75
76/*
77 * decode driven by state machine
78 */
79#define	S_GROUND	0	/* haven't seen escape char */
80#define	S_START		1	/* start decoding special sequence */
81#define	S_META		2	/* metachar started (M) */
82#define	S_META1		3	/* metachar more, regular char (-) */
83#define	S_CTRL		4	/* control char started (^) */
84#define	S_OCTAL2	5	/* octal digit 2 */
85#define	S_OCTAL3	6	/* octal digit 3 */
86
87#define	isoctal(c)	(((u_char)(c)) >= '0' && ((u_char)(c)) <= '7')
88
89/*
90 * unvis - decode characters previously encoded by vis
91 */
92#ifndef HAVE_UNVIS
93int
94unvis(char *cp, int c, int *astate, int flag)
95{
96
97	_DIAGASSERT(cp != NULL);
98	_DIAGASSERT(astate != NULL);
99
100	if (flag & UNVIS_END) {
101		if (*astate == S_OCTAL2 || *astate == S_OCTAL3) {
102			*astate = S_GROUND;
103			return (UNVIS_VALID);
104		}
105		return (*astate == S_GROUND ? UNVIS_NOCHAR : UNVIS_SYNBAD);
106	}
107
108	switch (*astate) {
109
110	case S_GROUND:
111		*cp = 0;
112		if (c == '\\') {
113			*astate = S_START;
114			return (0);
115		}
116		*cp = c;
117		return (UNVIS_VALID);
118
119	case S_START:
120		switch(c) {
121		case '\\':
122			*cp = c;
123			*astate = S_GROUND;
124			return (UNVIS_VALID);
125		case '0': case '1': case '2': case '3':
126		case '4': case '5': case '6': case '7':
127			*cp = (c - '0');
128			*astate = S_OCTAL2;
129			return (0);
130		case 'M':
131			*cp = (char)0200;
132			*astate = S_META;
133			return (0);
134		case '^':
135			*astate = S_CTRL;
136			return (0);
137		case 'n':
138			*cp = '\n';
139			*astate = S_GROUND;
140			return (UNVIS_VALID);
141		case 'r':
142			*cp = '\r';
143			*astate = S_GROUND;
144			return (UNVIS_VALID);
145		case 'b':
146			*cp = '\b';
147			*astate = S_GROUND;
148			return (UNVIS_VALID);
149		case 'a':
150			*cp = '\007';
151			*astate = S_GROUND;
152			return (UNVIS_VALID);
153		case 'v':
154			*cp = '\v';
155			*astate = S_GROUND;
156			return (UNVIS_VALID);
157		case 't':
158			*cp = '\t';
159			*astate = S_GROUND;
160			return (UNVIS_VALID);
161		case 'f':
162			*cp = '\f';
163			*astate = S_GROUND;
164			return (UNVIS_VALID);
165		case 's':
166			*cp = ' ';
167			*astate = S_GROUND;
168			return (UNVIS_VALID);
169		case 'E':
170			*cp = '\033';
171			*astate = S_GROUND;
172			return (UNVIS_VALID);
173		case '\n':
174			/*
175			 * hidden newline
176			 */
177			*astate = S_GROUND;
178			return (UNVIS_NOCHAR);
179		case '$':
180			/*
181			 * hidden marker
182			 */
183			*astate = S_GROUND;
184			return (UNVIS_NOCHAR);
185		}
186		*astate = S_GROUND;
187		return (UNVIS_SYNBAD);
188
189	case S_META:
190		if (c == '-')
191			*astate = S_META1;
192		else if (c == '^')
193			*astate = S_CTRL;
194		else {
195			*astate = S_GROUND;
196			return (UNVIS_SYNBAD);
197		}
198		return (0);
199
200	case S_META1:
201		*astate = S_GROUND;
202		*cp |= c;
203		return (UNVIS_VALID);
204
205	case S_CTRL:
206		if (c == '?')
207			*cp |= 0177;
208		else
209			*cp |= c & 037;
210		*astate = S_GROUND;
211		return (UNVIS_VALID);
212
213	case S_OCTAL2:	/* second possible octal digit */
214		if (isoctal(c)) {
215			/*
216			 * yes - and maybe a third
217			 */
218			*cp = (*cp << 3) + (c - '0');
219			*astate = S_OCTAL3;
220			return (0);
221		}
222		/*
223		 * no - done with current sequence, push back passed char
224		 */
225		*astate = S_GROUND;
226		return (UNVIS_VALIDPUSH);
227
228	case S_OCTAL3:	/* third possible octal digit */
229		*astate = S_GROUND;
230		if (isoctal(c)) {
231			*cp = (*cp << 3) + (c - '0');
232			return (UNVIS_VALID);
233		}
234		/*
235		 * we were done, push back passed char
236		 */
237		return (UNVIS_VALIDPUSH);
238
239	default:
240		/*
241		 * decoder in unknown state - (probably uninitialized)
242		 */
243		*astate = S_GROUND;
244		return (UNVIS_SYNBAD);
245	}
246}
247#endif
248
249/*
250 * strunvis - decode src into dst
251 *
252 *	Number of chars decoded into dst is returned, -1 on error.
253 *	Dst is null terminated.
254 */
255
256#ifndef HAVE_STRUNVIS
257int
258strunvis(char *dst, const char *src)
259{
260	char c;
261	char *start = dst;
262	int state = 0;
263
264	_DIAGASSERT(src != NULL);
265	_DIAGASSERT(dst != NULL);
266
267	while ((c = *src++) != '\0') {
268	again:
269		switch (unvis(dst, c, &state, 0)) {
270		case UNVIS_VALID:
271			dst++;
272			break;
273		case UNVIS_VALIDPUSH:
274			dst++;
275			goto again;
276		case 0:
277		case UNVIS_NOCHAR:
278			break;
279		default:
280			return (-1);
281		}
282	}
283	if (unvis(dst, c, &state, UNVIS_END) == UNVIS_VALID)
284		dst++;
285	*dst = '\0';
286	return (dst - start);
287}
288#endif
289