[unix-history] / usr / src / lib / libc / gen / unvis.c

/*-
 * Copyright (c) 1989 The Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)unvis.c	1.4 (Berkeley) 2/23/91";
#endif /* LIBC_SCCS and not lint */

#include <sys/types.h>
#include <ctype.h>
#include <vis.h>

/*
 * decode driven by state machine
 */
#define	S_GROUND	0	/* haven't seen escape char */
#define	S_START		1	/* start decoding special sequence */
#define	S_META		2	/* metachar started (M) */
#define	S_META1		3	/* metachar more, regular char (-) */
#define	S_CTRL		4	/* control char started (^) */
#define	S_OCTAL2	5	/* octal digit 2 */
#define	S_OCTAL3	6	/* octal digit 3 */

#define	isoctal(c)	(((u_char)(c)) >= '0' && ((u_char)(c)) <= '7')

/*
 * unvis - decode characters previously encoded by vis
 */
int
#if __STDC__
unvis(char *cp, char c, int *astate, int flag)
#else
unvis(cp, c, astate, flag)
	char *cp, c;
	int *astate, flag;
#endif
{

	if (flag & UNVIS_END) {
		if (*astate == S_OCTAL2 || *astate == S_OCTAL3) {
			*astate = S_GROUND;
			return (UNVIS_VALID);
		} 
		return (*astate == S_GROUND ? UNVIS_NOCHAR : UNVIS_SYNBAD);
	}

	switch (*astate) {

	case S_GROUND:
		*cp = 0;
		if (c == '\\') {
			*astate = S_START;
			return (0);
		} 
		*cp = c;
		return (UNVIS_VALID);

	case S_START:
		switch(c) {
		case '\\':
			*cp = c;
			*astate = S_GROUND;
			return (UNVIS_VALID);
		case '0': case '1': case '2': case '3':
		case '4': case '5': case '6': case '7':
			*cp = (c - '0');
			*astate = S_OCTAL2;
			return (0);
		case 'M':
			*cp = 0200;
			*astate = S_META;
			return (0);
		case '^':
			*astate = S_CTRL;
			return (0);
		case 'n':
			*cp = '\n';
			*astate = S_GROUND;
			return (UNVIS_VALID);
		case 'r':
			*cp = '\r';
			*astate = S_GROUND;
			return (UNVIS_VALID);
		case 'b':
			*cp = '\b';
			*astate = S_GROUND;
			return (UNVIS_VALID);
		case 'a':
			*cp = '\007';
			*astate = S_GROUND;
			return (UNVIS_VALID);
		case 'v':
			*cp = '\v';
			*astate = S_GROUND;
			return (UNVIS_VALID);
		case 't':
			*cp = '\t';
			*astate = S_GROUND;
			return (UNVIS_VALID);
		case 'f':
			*cp = '\f';
			*astate = S_GROUND;
			return (UNVIS_VALID);
		case 's':
			*cp = ' ';
			*astate = S_GROUND;
			return (UNVIS_VALID);
		case 'E':
			*cp = '\033';
			*astate = S_GROUND;
			return (UNVIS_VALID);
		case '\n':
			/*
			 * hidden newline
			 */
			*astate = S_GROUND;
			return (UNVIS_NOCHAR);
		case '$':
			/*
			 * hidden marker
			 */
			*astate = S_GROUND;
			return (UNVIS_NOCHAR);
		}
		*astate = S_GROUND;
		return (UNVIS_SYNBAD);
		 
	case S_META:
		if (c == '-')
			*astate = S_META1;
		else if (c == '^')
			*astate = S_CTRL;
		else {
			*astate = S_GROUND;
			return (UNVIS_SYNBAD);
		}
		return (0);
		 
	case S_META1:
		*astate = S_GROUND;
		*cp |= c;
		return (UNVIS_VALID);
		 
	case S_CTRL:
		if (c == '?')
			*cp |= 0177;
		else
			*cp |= c & 037;
		*astate = S_GROUND;
		return (UNVIS_VALID);

	case S_OCTAL2:	/* second possible octal digit */
		if (isoctal(c)) {
			/* 
			 * yes - and maybe a third 
			 */
			*cp = (*cp << 3) + (c - '0');
			*astate = S_OCTAL3;	
			return (0);
		} 
		/* 
		 * no - done with current sequence, push back passed char 
		 */
		*astate = S_GROUND;
		return (UNVIS_VALIDPUSH);

	case S_OCTAL3:	/* third possible octal digit */
		*astate = S_GROUND;
		if (isoctal(c)) {
			*cp = (*cp << 3) + (c - '0');
			return (UNVIS_VALID);
		}
		/*
		 * we were done, push back passed char
		 */
		return (UNVIS_VALIDPUSH);
			
	default:	
		/* 
		 * decoder in unknown state - (probably uninitialized) 
		 */
		*astate = S_GROUND;
		return (UNVIS_SYNBAD);
	}
}

/*
 * strunvis - decode src into dst 
 *
 *	Number of chars decoded into dst is returned, -1 on error.
 *	Dst is null terminated.
 */

int
strunvis(dst, src)
	register char *dst;
	register const char *src;
{
	register char c;
	char *start = dst;
	int state = 0;

	while (c = *src++) {
	again:
		switch (unvis(dst, c, &state, 0)) {
		case UNVIS_VALID:
			dst++;
			break;
		case UNVIS_VALIDPUSH:
			dst++;
			goto again;
		case 0:
		case UNVIS_NOCHAR:
			break;
		default:
			return (-1);
		}
	}
	if (unvis(dst, c, &state, UNVIS_END) == UNVIS_VALID)
		dst++;
	*dst = '\0';
	return (dst - start);
}
Commit	Line	Data
8168e750 WJ	1	/*-
	2	* Copyright (c) 1989 The Regents of the University of California.
	3	* All rights reserved.
	4	*
	5	* Redistribution and use in source and binary forms, with or without
	6	* modification, are permitted provided that the following conditions
	7	* are met:
	8	* 1. Redistributions of source code must retain the above copyright
	9	* notice, this list of conditions and the following disclaimer.
	10	* 2. Redistributions in binary form must reproduce the above copyright
	11	* notice, this list of conditions and the following disclaimer in the
	12	* documentation and/or other materials provided with the distribution.
	13	* 3. All advertising materials mentioning features or use of this software
	14	* must display the following acknowledgement:
	15	* This product includes software developed by the University of
	16	* California, Berkeley and its contributors.
	17	* 4. Neither the name of the University nor the names of its contributors
	18	* may be used to endorse or promote products derived from this software
	19	* without specific prior written permission.
	20	*
	21	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	22	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	23	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	24	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	25	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	26	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	27	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	28	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	29	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	30	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	31	* SUCH DAMAGE.
	32	*/
	33
	34	#if defined(LIBC_SCCS) && !defined(lint)
	35	static char sccsid[] = "@(#)unvis.c 1.4 (Berkeley) 2/23/91";
	36	#endif /* LIBC_SCCS and not lint */
	37
	38	#include <sys/types.h>
	39	#include <ctype.h>
	40	#include <vis.h>
	41
	42	/*
	43	* decode driven by state machine
	44	*/
	45	#define S_GROUND 0 /* haven't seen escape char */
	46	#define S_START 1 /* start decoding special sequence */
	47	#define S_META 2 /* metachar started (M) */
	48	#define S_META1 3 /* metachar more, regular char (-) */
	49	#define S_CTRL 4 /* control char started (^) */
	50	#define S_OCTAL2 5 /* octal digit 2 */
	51	#define S_OCTAL3 6 /* octal digit 3 */
	52
	53	#define isoctal(c) (((u_char)(c)) >= '0' && ((u_char)(c)) <= '7')
	54
	55	/*
	56	* unvis - decode characters previously encoded by vis
	57	*/
	58	int
	59	#if __STDC__
	60	unvis(char cp, char c, int astate, int flag)
	61	#else
	62	unvis(cp, c, astate, flag)
	63	char *cp, c;
	64	int *astate, flag;
65	#endif
66	{
67
68	if (flag & UNVIS_END) {
69	if (astate == S_OCTAL2 \|\| astate == S_OCTAL3) {
70	*astate = S_GROUND;
71	return (UNVIS_VALID);
72	}
73	return (*astate == S_GROUND ? UNVIS_NOCHAR : UNVIS_SYNBAD);
74	}
75
76	switch (*astate) {
77
78	case S_GROUND:
79	*cp = 0;
80	if (c == '\\') {
81	*astate = S_START;
82	return (0);
83	}
84	*cp = c;
85	return (UNVIS_VALID);
86
87	case S_START:
88	switch(c) {
89	case '\\':
90	*cp = c;
91	*astate = S_GROUND;
92	return (UNVIS_VALID);
93	case '0': case '1': case '2': case '3':
94	case '4': case '5': case '6': case '7':
95	*cp = (c - '0');
96	*astate = S_OCTAL2;
97	return (0);
98	case 'M':
99	*cp = 0200;
100	*astate = S_META;
101	return (0);
102	case '^':
103	*astate = S_CTRL;
104	return (0);
105	case 'n':
106	*cp = '\n';
107	*astate = S_GROUND;
108	return (UNVIS_VALID);
109	case 'r':
110	*cp = '\r';
111	*astate = S_GROUND;
112	return (UNVIS_VALID);
113	case 'b':
114	*cp = '\b';
115	*astate = S_GROUND;
116	return (UNVIS_VALID);
117	case 'a':
118	*cp = '\007';
119	*astate = S_GROUND;
120	return (UNVIS_VALID);
121	case 'v':
122	*cp = '\v';
123	*astate = S_GROUND;
124	return (UNVIS_VALID);
125	case 't':
126	*cp = '\t';
127	*astate = S_GROUND;
128	return (UNVIS_VALID);
129	case 'f':
130	*cp = '\f';
131	*astate = S_GROUND;
132	return (UNVIS_VALID);
133	case 's':
134	*cp = ' ';
135	*astate = S_GROUND;
136	return (UNVIS_VALID);
137	case 'E':
138	*cp = '\033';
139	*astate = S_GROUND;
140	return (UNVIS_VALID);
141	case '\n':
142	/*
143	* hidden newline
144	*/
145	*astate = S_GROUND;
146	return (UNVIS_NOCHAR);
147	case '$':
148	/*
149	* hidden marker
150	*/
151	*astate = S_GROUND;
152	return (UNVIS_NOCHAR);
153	}
154	*astate = S_GROUND;
155	return (UNVIS_SYNBAD);
156
157	case S_META:
158	if (c == '-')
159	*astate = S_META1;
160	else if (c == '^')
161	*astate = S_CTRL;
162	else {
163	*astate = S_GROUND;
164	return (UNVIS_SYNBAD);
165	}
166	return (0);
167
168	case S_META1:
169	*astate = S_GROUND;
170	*cp \|= c;
171	return (UNVIS_VALID);
172
173	case S_CTRL:
174	if (c == '?')
175	*cp \|= 0177;
176	else
177	*cp \|= c & 037;
178	*astate = S_GROUND;
179	return (UNVIS_VALID);
180
181	case S_OCTAL2: /* second possible octal digit */
182	if (isoctal(c)) {
183	/*
184	* yes - and maybe a third
185	*/
186	cp = (cp << 3) + (c - '0');
187	*astate = S_OCTAL3;
188	return (0);
189	}
190	/*
191	* no - done with current sequence, push back passed char
192	*/
193	*astate = S_GROUND;
194	return (UNVIS_VALIDPUSH);
195
196	case S_OCTAL3: /* third possible octal digit */
197	*astate = S_GROUND;
198	if (isoctal(c)) {
199	cp = (cp << 3) + (c - '0');
200	return (UNVIS_VALID);
201	}
202	/*
203	* we were done, push back passed char
204	*/
205	return (UNVIS_VALIDPUSH);
206
207	default:
208	/*
209	* decoder in unknown state - (probably uninitialized)
210	*/
211	*astate = S_GROUND;
212	return (UNVIS_SYNBAD);
213	}
214	}
215
216	/*
217	* strunvis - decode src into dst
218	*
219	* Number of chars decoded into dst is returned, -1 on error.
220	* Dst is null terminated.
221	*/
222
223	int
224	strunvis(dst, src)
225	register char *dst;
226	register const char *src;
227	{
228	register char c;
229	char *start = dst;
230	int state = 0;
231
232	while (c = *src++) {
233	again:
234	switch (unvis(dst, c, &state, 0)) {
235	case UNVIS_VALID:
236	dst++;
237	break;
238	case UNVIS_VALIDPUSH:
239	dst++;
240	goto again;
241	case 0:
242	case UNVIS_NOCHAR:
243	break;
244	default:
245	return (-1);
246	}
247	}
248	if (unvis(dst, c, &state, UNVIS_END) == UNVIS_VALID)
249	dst++;
250	*dst = '\0';
251	return (dst - start);
252	}