[apple/libc.git] / gen / FreeBSD / unvis.c

/*-
 * Copyright (c) 1989, 1993
 *	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.
 * 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	8.1 (Berkeley) 6/4/93";
#endif /* LIBC_SCCS and not lint */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD: src/lib/libc/gen/unvis.c,v 1.10 2007/01/09 00:27:56 imp Exp $");

#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	S_HEX2		7	/* hex digit 2 */

#define	S_HTTP		0x080	/* %HEXHEX escape */

#define	isoctal(c)	(((u_char)(c)) >= '0' && ((u_char)(c)) <= '7')
#define	ishex(c)	((((u_char)(c)) >= '0' && ((u_char)(c)) <= '9') || (((u_char)(c)) >= 'a' && ((u_char)(c)) <= 'f'))

/*
 * unvis - decode characters previously encoded by vis
 */
int
unvis(char *cp, int c, int *astate, int flag)
{

	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 & ~S_HTTP) {

	case S_GROUND:
		*cp = 0;
		if (c == '\\') {
			*astate = S_START;
			return (0);
		}
		if (flag & VIS_HTTPSTYLE && c == '%') {
			*astate = S_START | S_HTTP;
			return (0);
		}
		*cp = c;
		return (UNVIS_VALID);

	case S_START:
		if (*astate & S_HTTP) {
		    if (ishex(tolower(c))) {
			*cp = isdigit(c) ? (c - '0') : (tolower(c) - 'a');
			*astate = S_HEX2;
			return (0);
		    }
		}
		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);

	case S_HEX2:	/* second mandatory hex digit */
		if (ishex(tolower(c))) {
			*cp = (isdigit(c) ? (*cp << 4) + (c - '0') : (*cp << 4) + (tolower(c) - 'a' + 10));
		}
		*astate = S_GROUND;
		return (UNVIS_VALID);

	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(char *dst, const char *src)
{
	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);
}

int
strunvisx(char *dst, const char *src, int flag)
{
	char c;
	char *start = dst;
	int state = 0;
    
	while ( (c = *src++) ) {
	again:
		switch (unvis(dst, c, &state, flag)) {
		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
9385eb3d	1	/*-
e9ce8d39 A	2	* Copyright (c) 1989, 1993
	3	* The Regents of the University of California. 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.
e9ce8d39 A	13	* 4. Neither the name of the University nor the names of its contributors
	14	* may be used to endorse or promote products derived from this software
	15	* without specific prior written permission.
	16	*
	17	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	18	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	19	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	20	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	21	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	22	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	23	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	24	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	25	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	26	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	27	* SUCH DAMAGE.
	28	*/
	29
9385eb3d A	30	#if defined(LIBC_SCCS) && !defined(lint)
	31	static char sccsid[] = "@(#)unvis.c 8.1 (Berkeley) 6/4/93";
	32	#endif /* LIBC_SCCS and not lint */
	33	#include <sys/cdefs.h>
1f2f436a	34	__FBSDID("$FreeBSD: src/lib/libc/gen/unvis.c,v 1.10 2007/01/09 00:27:56 imp Exp $");
e9ce8d39 A	35
	36	#include <sys/types.h>
	37	#include <ctype.h>
	38	#include <vis.h>
	39
	40	/*
	41	* decode driven by state machine
	42	*/
	43	#define S_GROUND 0 /* haven't seen escape char */
	44	#define S_START 1 /* start decoding special sequence */
	45	#define S_META 2 /* metachar started (M) */
	46	#define S_META1 3 /* metachar more, regular char (-) */
	47	#define S_CTRL 4 /* control char started (^) */
	48	#define S_OCTAL2 5 /* octal digit 2 */
	49	#define S_OCTAL3 6 /* octal digit 3 */
9385eb3d A	50	#define S_HEX2 7 /* hex digit 2 */
	51
	52	#define S_HTTP 0x080 /* %HEXHEX escape */
e9ce8d39 A	53
e9ce8d39 A	54	#define isoctal(c) (((u_char)(c)) >= '0' && ((u_char)(c)) <= '7')
9385eb3d	55	#define ishex(c) ((((u_char)(c)) >= '0' && ((u_char)(c)) <= '9') \|\| (((u_char)(c)) >= 'a' && ((u_char)(c)) <= 'f'))
e9ce8d39 A	56
	57	/*
	58	* unvis - decode characters previously encoded by vis
	59	*/
	60	int
3d9156a7	61	unvis(char cp, int c, int astate, int flag)
e9ce8d39 A	62	{
	63
	64	if (flag & UNVIS_END) {
	65	if (astate == S_OCTAL2 \|\| astate == S_OCTAL3) {
	66	*astate = S_GROUND;
	67	return (UNVIS_VALID);
9385eb3d	68	}
e9ce8d39 A	69	return (*astate == S_GROUND ? UNVIS_NOCHAR : UNVIS_SYNBAD);
	70	}
	71
9385eb3d	72	switch (*astate & ~S_HTTP) {
e9ce8d39 A	73
	74	case S_GROUND:
	75	*cp = 0;
	76	if (c == '\\') {
	77	*astate = S_START;
	78	return (0);
9385eb3d A	79	}
	80	if (flag & VIS_HTTPSTYLE && c == '%') {
	81	*astate = S_START \| S_HTTP;
	82	return (0);
	83	}
e9ce8d39 A	84	*cp = c;
	85	return (UNVIS_VALID);
	86
	87	case S_START:
9385eb3d A	88	if (*astate & S_HTTP) {
	89	if (ishex(tolower(c))) {
	90	*cp = isdigit(c) ? (c - '0') : (tolower(c) - 'a');
	91	*astate = S_HEX2;
	92	return (0);
	93	}
	94	}
e9ce8d39 A	95	switch(c) {
	96	case '\\':
	97	*cp = c;
	98	*astate = S_GROUND;
	99	return (UNVIS_VALID);
	100	case '0': case '1': case '2': case '3':
	101	case '4': case '5': case '6': case '7':
	102	*cp = (c - '0');
	103	*astate = S_OCTAL2;
	104	return (0);
	105	case 'M':
	106	*cp = 0200;
	107	*astate = S_META;
	108	return (0);
	109	case '^':
	110	*astate = S_CTRL;
	111	return (0);
	112	case 'n':
	113	*cp = '\n';
	114	*astate = S_GROUND;
	115	return (UNVIS_VALID);
	116	case 'r':
	117	*cp = '\r';
	118	*astate = S_GROUND;
	119	return (UNVIS_VALID);
	120	case 'b':
	121	*cp = '\b';
	122	*astate = S_GROUND;
	123	return (UNVIS_VALID);
	124	case 'a':
	125	*cp = '\007';
	126	*astate = S_GROUND;
	127	return (UNVIS_VALID);
	128	case 'v':
	129	*cp = '\v';
	130	*astate = S_GROUND;
	131	return (UNVIS_VALID);
	132	case 't':
	133	*cp = '\t';
	134	*astate = S_GROUND;
	135	return (UNVIS_VALID);
	136	case 'f':
	137	*cp = '\f';
	138	*astate = S_GROUND;
	139	return (UNVIS_VALID);
	140	case 's':
	141	*cp = ' ';
	142	*astate = S_GROUND;
	143	return (UNVIS_VALID);
	144	case 'E':
	145	*cp = '\033';
	146	*astate = S_GROUND;
	147	return (UNVIS_VALID);
	148	case '\n':
	149	/*
	150	* hidden newline
	151	*/
	152	*astate = S_GROUND;
	153	return (UNVIS_NOCHAR);
	154	case '$':
	155	/*
	156	* hidden marker
	157	*/
	158	*astate = S_GROUND;
159	return (UNVIS_NOCHAR);
160	}
161	*astate = S_GROUND;
162	return (UNVIS_SYNBAD);
9385eb3d	163
e9ce8d39 A	164	case S_META:
	165	if (c == '-')
	166	*astate = S_META1;
	167	else if (c == '^')
	168	*astate = S_CTRL;
	169	else {
	170	*astate = S_GROUND;
	171	return (UNVIS_SYNBAD);
	172	}
	173	return (0);
9385eb3d	174
e9ce8d39 A	175	case S_META1:
	176	*astate = S_GROUND;
	177	*cp \|= c;
	178	return (UNVIS_VALID);
9385eb3d	179
e9ce8d39 A	180	case S_CTRL:
	181	if (c == '?')
	182	*cp \|= 0177;
	183	else
	184	*cp \|= c & 037;
	185	*astate = S_GROUND;
	186	return (UNVIS_VALID);
	187
	188	case S_OCTAL2: /* second possible octal digit */
	189	if (isoctal(c)) {
9385eb3d A	190	/*
9385eb3d A	191	* yes - and maybe a third
e9ce8d39 A	192	*/
e9ce8d39 A	193	cp = (cp << 3) + (c - '0');
9385eb3d	194	*astate = S_OCTAL3;
e9ce8d39	195	return (0);
9385eb3d A	196	}
	197	/*
	198	* no - done with current sequence, push back passed char
e9ce8d39 A	199	*/
	200	*astate = S_GROUND;
	201	return (UNVIS_VALIDPUSH);
	202
	203	case S_OCTAL3: /* third possible octal digit */
	204	*astate = S_GROUND;
	205	if (isoctal(c)) {
	206	cp = (cp << 3) + (c - '0');
	207	return (UNVIS_VALID);
	208	}
	209	/*
	210	* we were done, push back passed char
	211	*/
	212	return (UNVIS_VALIDPUSH);
9385eb3d A	213
	214	case S_HEX2: /* second mandatory hex digit */
	215	if (ishex(tolower(c))) {
	216	cp = (isdigit(c) ? (cp << 4) + (c - '0') : (*cp << 4) + (tolower(c) - 'a' + 10));
	217	}
	218	*astate = S_GROUND;
	219	return (UNVIS_VALID);
	220
	221	default:
	222	/*
	223	* decoder in unknown state - (probably uninitialized)
e9ce8d39 A	224	*/
	225	*astate = S_GROUND;
	226	return (UNVIS_SYNBAD);
	227	}
	228	}
	229
	230	/*
9385eb3d	231	* strunvis - decode src into dst
e9ce8d39 A	232	*
	233	* Number of chars decoded into dst is returned, -1 on error.
	234	* Dst is null terminated.
	235	*/
	236
	237	int
3d9156a7	238	strunvis(char dst, const char src)
e9ce8d39	239	{
9385eb3d	240	char c;
e9ce8d39 A	241	char *start = dst;
	242	int state = 0;
	243
9385eb3d	244	while ( (c = *src++) ) {
e9ce8d39 A	245	again:
	246	switch (unvis(dst, c, &state, 0)) {
	247	case UNVIS_VALID:
	248	dst++;
	249	break;
	250	case UNVIS_VALIDPUSH:
	251	dst++;
	252	goto again;
	253	case 0:
	254	case UNVIS_NOCHAR:
	255	break;
	256	default:
	257	return (-1);
	258	}
	259	}
	260	if (unvis(dst, c, &state, UNVIS_END) == UNVIS_VALID)
	261	dst++;
	262	*dst = '\0';
	263	return (dst - start);
	264	}
9385eb3d A	265
9385eb3d A	266	int
3d9156a7	267	strunvisx(char dst, const char src, int flag)
9385eb3d A	268	{
	269	char c;
	270	char *start = dst;
	271	int state = 0;
	272
	273	while ( (c = *src++) ) {
	274	again:
	275	switch (unvis(dst, c, &state, flag)) {
	276	case UNVIS_VALID:
	277	dst++;
	278	break;
	279	case UNVIS_VALIDPUSH:
	280	dst++;
	281	goto again;
	282	case 0:
	283	case UNVIS_NOCHAR:
	284	break;
	285	default:
	286	return (-1);
	287	}
	288	}
	289	if (unvis(dst, c, &state, UNVIS_END) == UNVIS_VALID)
	290	dst++;
	291	*dst = '\0';
	292	return (dst - start);
	293	}