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File: [local] / src / usr.bin / tr / str.c (download)

Revision 1.11, Tue Oct 27 23:59:46 2009 UTC (14 years, 7 months ago) by deraadt
Branch: MAIN
CVS Tags: OPENBSD_5_2_BASE, OPENBSD_5_2, OPENBSD_5_1_BASE, OPENBSD_5_1, OPENBSD_5_0_BASE, OPENBSD_5_0, OPENBSD_4_9_BASE, OPENBSD_4_9, OPENBSD_4_8_BASE, OPENBSD_4_8, OPENBSD_4_7_BASE, OPENBSD_4_7
Changes since 1.10: +1 -8 lines

rcsid[] and sccsid[] and copyright[] are essentially unmaintained (and
unmaintainable).  these days, people use source.  these id's do not provide
any benefit, and do hurt the small install media
(the 33,000 line diff is essentially mechanical)
ok with the idea millert, ok dms

/*	$OpenBSD: str.c,v 1.11 2009/10/27 23:59:46 deraadt Exp $	*/
/*	$NetBSD: str.c,v 1.7 1995/08/31 22:13:47 jtc Exp $	*/

/*-
 * Copyright (c) 1991, 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. 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.
 */

#include <sys/cdefs.h>
#include <sys/types.h>

#include <errno.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <err.h>

#include "extern.h"

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

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

	switch (s->state) {
	case EOS:
		return (0);
	case INFINITE:
		return (1);
	case NORMAL:
		switch (ch = *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);
	default:
		return 0;
	}
	/* NOTREACHED */
}

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

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

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

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

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

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

	if ((cp->set = p = calloc(NCHARS + 1, sizeof(int))) == NULL)
		errx(1, "no memory for a class");
	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;
	unsigned char *savestart;

	savestart = s->str;
	stopval = *++s->str == '\\' ? backslash(s) : *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(*s->str)) {
			s->cnt = strtol((char *)s->str, &ep, 0);
			if (*ep == ']') {
				s->str = (unsigned char *)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)
	STR *s;
{
	int ch, cnt, val;

	for (cnt = val = 0;;) {
		ch = *++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);
	}
}