/* vi: set sw=4 ts=4: */
/*
 * Copyright (c) 1988, 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.
 * 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 0
#ifndef lint
static const char copyright[] = "@(#) Copyright (c) 1988, 1993\n\
	The Regents of the University of California.  All rights reserved.\n";
#endif							/* not lint */

#ifndef lint
#if 0
static char sccsid[] = "@(#)tr.c	8.2 (Berkeley) 5/4/95";
#endif
static const char rcsid[] =

	"$Id: tr.c,v 1.4 2000/04/17 16:44:46 erik Exp $";
#endif							/* not lint */
#endif							/* #if 0 */

#include "internal.h"
#include <locale.h>
#include <sys/types.h>
#include <sys/cdefs.h>
#include <sys/types.h>

#include <err.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include <ctype.h>
#include <err.h>
#include <stddef.h>

typedef struct {
	enum { STRING1, STRING2 } which;
	enum { EOS, INFINITE, NORMAL, RANGE, SEQUENCE, SET } state;
	int cnt;					/* character count */
	int lastch;					/* last character */
	int equiv[2];				/* equivalence set */
	int *set;					/* set of characters */
	char *str;					/* user's string */
} STR;

#include <limits.h>
#define	NCHARS	(UCHAR_MAX + 1)	/* Number of possible characters. */
#define	OOBCH	(UCHAR_MAX + 1)	/* Out of band character value. */

static int next __P((STR *));

static int string1[NCHARS] = {
	0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,	/* ASCII */
	0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
	0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
	0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
	0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27,
	0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
	0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
	0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f,
	0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47,
	0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f,
	0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57,
	0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f,
	0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67,
	0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f,
	0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77,
	0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f,
	0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
	0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f,
	0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97,
	0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f,
	0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7,
	0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf,
	0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7,
	0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf,
	0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7,
	0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd, 0xce, 0xcf,
	0xd0, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7,
	0xd8, 0xd9, 0xda, 0xdb, 0xdc, 0xdd, 0xde, 0xdf,
	0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7,
	0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef,
	0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7,
	0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff,
}, string2[NCHARS];

STR s1 = { STRING1, NORMAL, 0, OOBCH, {0, OOBCH}, NULL, NULL };
STR s2 = { STRING2, NORMAL, 0, OOBCH, {0, OOBCH}, NULL, NULL };

static void setup(string, arg, str, cflag)
int *string;
char *arg;
STR *str;
int cflag;
{
	register int cnt, *p;

	str->str = arg;
	bzero(string, NCHARS * sizeof(int));

	while (next(str))
		string[str->lastch] = 1;
	if (cflag)
		for (p = string, cnt = NCHARS; cnt--; ++p)
			*p = !*p;
}

static void tr_usage()
{
	usage( "\ttr [-cdsu] string1 [string2]\n\n"
		   "Translate, squeeze, and/or delete characters from standard\n"
		   "input, writing to standard output.\n");
}


extern int tr_main(argc, argv)
int argc;
char **argv;
{
	register int ch, cnt, lastch, *p;
	int cflag, dflag, sflag, isstring2;

	(void) setlocale(LC_CTYPE, "");

	cflag = dflag = sflag = 0;
	while ((ch = getopt(argc, argv, "cdsu")) != -1)
		switch ((char) ch) {
		case 'c':
			cflag = 1;
			break;
		case 'd':
			dflag = 1;
			break;
		case 's':
			sflag = 1;
			break;
		case 'u':
			setbuf(stdout, (char *) NULL);
			break;
		case '?':
		default:
			tr_usage();
		}
	argc -= optind;
	argv += optind;

	switch (argc) {
	case 0:
	default:
		tr_usage();
		/* NOTREACHED */
	case 1:
		isstring2 = 0;
		break;
	case 2:
		isstring2 = 1;
		break;
	}

	/*
	 * tr -ds [-c] string1 string2
	 * Delete all characters (or complemented characters) in string1.
	 * Squeeze all characters in string2.
	 */
	if (dflag && sflag) {
		if (!isstring2)
			tr_usage();

		setup(string1, argv[0], &s1, cflag);
		setup(string2, argv[1], &s2, 0);

		for (lastch = OOBCH; (ch = getchar()) != EOF;)
			if (!string1[ch] && (!string2[ch] || lastch != ch)) {
				lastch = ch;
				(void) putchar(ch);
			}
		exit(0);
	}

	/*
	 * tr -d [-c] string1
	 * Delete all characters (or complemented characters) in string1.
	 */
	if (dflag) {
		if (isstring2)
			tr_usage();

		setup(string1, argv[0], &s1, cflag);

		while ((ch = getchar()) != EOF)
			if (!string1[ch])
				(void) putchar(ch);
		exit(0);
	}

	/*
	 * tr -s [-c] string1
	 * Squeeze all characters (or complemented characters) in string1.
	 */
	if (sflag && !isstring2) {
		setup(string1, argv[0], &s1, cflag);

		for (lastch = OOBCH; (ch = getchar()) != EOF;)
			if (!string1[ch] || lastch != ch) {
				lastch = ch;
				(void) putchar(ch);
			}
		exit(0);
	}

	/*
	 * tr [-cs] string1 string2
	 * Replace all characters (or complemented characters) in string1 with
	 * the character in the same position in string2.  If the -s option is
	 * specified, squeeze all the characters in string2.
	 */
	if (!isstring2)
		tr_usage();

	s1.str = argv[0];
	s2.str = argv[1];

	if (cflag)
		for (cnt = NCHARS, p = string1; cnt--;)
			*p++ = OOBCH;

	if (!next(&s2))
		errx(1, "empty string2");

	/* If string2 runs out of characters, use the last one specified. */
	if (sflag)
		while (next(&s1)) {
			string1[s1.lastch] = ch = s2.lastch;
			string2[ch] = 1;
			(void) next(&s2);
	} else
		while (next(&s1)) {
			string1[s1.lastch] = ch = s2.lastch;
			(void) next(&s2);
		}

	if (cflag)
		for (cnt = 0, p = string1; cnt < NCHARS; ++p, ++cnt)
			*p = *p == OOBCH ? ch : cnt;

	if (sflag)
		for (lastch = OOBCH; (ch = getchar()) != EOF;) {
			ch = string1[ch];
			if (!string2[ch] || lastch != ch) {
				lastch = ch;
				(void) putchar(ch);
			}
	} else
		while ((ch = getchar()) != EOF)
			(void) putchar(string1[ch]);
	exit(0);
}

static int backslash __P((STR *));
static int bracket __P((STR *));
static int c_class __P((const void *, const void *));
static void genclass __P((STR *));
static void genequiv __P((STR *));
static int genrange __P((STR *));
static void genseq __P((STR *));

static int next(s)
register STR *s;
{
	register int ch;

	switch (s->state) {
	case EOS:
		return (0);
	case INFINITE:
		return (1);
	case NORMAL:
		switch (ch = (u_char) * s->str) {
		case '\0':
			s->state = EOS;
			return (0);
		case '\\':
			s->lastch = backslash(s);
			break;
		case '[':
			if (bracket(s))
				return (next(s));
			/* FALLTHROUGH */
		default:
			++s->str;
			s->lastch = ch;
			break;
		}

		/* We can start a range at any time. */
		if (s->str[0] == '-' && genrange(s))
			return (next(s));
		return (1);
	case RANGE:
		if (s->cnt-- == 0) {
			s->state = NORMAL;
			return (next(s));
		}
		++s->lastch;
		return (1);
	case SEQUENCE:
		if (s->cnt-- == 0) {
			s->state = NORMAL;
			return (next(s));
		}
		return (1);
	case SET:
		if ((s->lastch = s->set[s->cnt++]) == OOBCH) {
			s->state = NORMAL;
			return (next(s));
		}
		return (1);
	}
	/* NOTREACHED */
	return (0);
}

static int bracket(s)
register STR *s;
{
	register char *p;

	switch (s->str[1]) {
	case ':':					/* "[:class:]" */
		if ((p = strstr(s->str + 2, ":]")) == NULL)
			return (0);
		*p = '\0';
		s->str += 2;
		genclass(s);
		s->str = p + 2;
		return (1);
	case '=':					/* "[=equiv=]" */
		if ((p = strstr(s->str + 2, "=]")) == NULL)
			return (0);
		s->str += 2;
		genequiv(s);
		return (1);
	default:					/* "[\###*n]" or "[#*n]" */
		if ((p = strpbrk(s->str + 2, "*]")) == NULL)
			return (0);
		if (p[0] != '*' || index(p, ']') == NULL)
			return (0);
		s->str += 1;
		genseq(s);
		return (1);
	}
	/* NOTREACHED */
}

typedef struct {
	char *name;
	int (*func) __P((int));
	int *set;
} CLASS;

static CLASS classes[] = {
#undef isalnum
	{"alnum", isalnum,},
#undef isalpha
	{"alpha", isalpha,},
/*#undef isblank
	{ "blank",  isblank,  },*/
#undef iscntrl
	{"cntrl", iscntrl,},
#undef isdigit
	{"digit", isdigit,},
#undef isgraph
	{"graph", isgraph,},
#undef islower
	{"lower", islower,},
#undef isprint
	{"print", isprint,},
#undef ispunct
	{"punct", ispunct,},
#undef isspace
	{"space", isspace,},
#undef isupper
	{"upper", isupper,},
#undef isxdigit
	{"xdigit", isxdigit,},
};

static void genclass(s)
STR *s;
{
	register int cnt, (*func) __P((int));
	CLASS *cp, tmp;
	int *p;

	tmp.name = s->str;
	if ((cp = (CLASS *) bsearch(&tmp, classes, sizeof(classes) /
								sizeof(CLASS), sizeof(CLASS),
								c_class)) == NULL) errx(1,
														"unknown class %s",
														s->str);

	cp->set = p = xmalloc((NCHARS + 1) * sizeof(int));
	bzero(p, (NCHARS + 1) * sizeof(int));

	for (cnt = 0, func = cp->func; cnt < NCHARS; ++cnt)
		if ((func) (cnt))
			*p++ = cnt;
	*p = OOBCH;

	s->cnt = 0;
	s->state = SET;
	s->set = cp->set;
}

static int c_class(a, b)
const void *a, *b;
{
	return (strcmp(((CLASS *) a)->name, ((CLASS *) b)->name));
}

/*
 * English doesn't have any equivalence classes, so for now
 * we just syntax check and grab the character.
 */
static void genequiv(s)
STR *s;
{
	if (*s->str == '\\') {
		s->equiv[0] = backslash(s);
		if (*s->str != '=')
			errx(1, "misplaced equivalence equals sign");
	} else {
		s->equiv[0] = s->str[0];
		if (s->str[1] != '=')
			errx(1, "misplaced equivalence equals sign");
	}
	s->str += 2;
	s->cnt = 0;
	s->state = SET;
	s->set = s->equiv;
}

static int genrange(s)
STR *s;
{
	int stopval;
	char *savestart;

	savestart = s->str;
	stopval = *++s->str == '\\' ? backslash(s) : (u_char) * s->str++;
	if (stopval < (u_char) s->lastch) {
		s->str = savestart;
		return (0);
	}
	s->cnt = stopval - s->lastch + 1;
	s->state = RANGE;
	--s->lastch;
	return (1);
}

static void genseq(s)
STR *s;
{
	char *ep;

	if (s->which == STRING1)
		errx(1, "sequences only valid in string2");

	if (*s->str == '\\')
		s->lastch = backslash(s);
	else
		s->lastch = *s->str++;
	if (*s->str != '*')
		errx(1, "misplaced sequence asterisk");

	switch (*++s->str) {
	case '\\':
		s->cnt = backslash(s);
		break;
	case ']':
		s->cnt = 0;
		++s->str;
		break;
	default:
		if (isdigit((u_char) * s->str)) {
			s->cnt = strtol(s->str, &ep, 0);
			if (*ep == ']') {
				s->str = ep + 1;
				break;
			}
		}
		errx(1, "illegal sequence count");
		/* NOTREACHED */
	}

	s->state = s->cnt ? SEQUENCE : INFINITE;
}

/*
 * Translate \??? into a character.  Up to 3 octal digits, if no digits either
 * an escape code or a literal character.
 */
static int backslash(s)
register STR *s;
{
	register int ch, cnt, val;

	for (cnt = val = 0;;) {
		ch = (u_char) * ++s->str;
		if (!isascii(ch) || !isdigit(ch))
			break;
		val = val * 8 + ch - '0';
		if (++cnt == 3) {
			++s->str;
			break;
		}
	}
	if (cnt)
		return (val);
	if (ch != '\0')
		++s->str;
	switch (ch) {
	case 'a':					/* escape characters */
		return ('\7');
	case 'b':
		return ('\b');
	case 'f':
		return ('\f');
	case 'n':
		return ('\n');
	case 'r':
		return ('\r');
	case 't':
		return ('\t');
	case 'v':
		return ('\13');
	case '\0':					/*  \" -> \ */
		s->state = EOS;
		return ('\\');
	default:					/* \x" -> x */
		return (ch);
	}
}