cmd/tr/str.c

/*
 * 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. 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.
 */

#include <sys/types.h>

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

#include "extern.h"

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

wint_t
next(s)
    STR *s;
{
    int is_octal;
    wint_t ch;
    wchar_t wch;
    size_t clen;

    switch (s->state) {
    case EOS:
        return (0);
    case INFINITE:
        return (1);
    case NORMAL:
        switch (*s->str) {
        case '\0':
            s->state = EOS;
            return (0);
        case '\\':
            s->lastch = backslash(s, &is_octal);
            break;
        case '[':
            if (bracket(s))
                return (next(s));
            /* FALLTHROUGH */
        default:
            clen = mbrtowc(&wch, s->str, MB_LEN_MAX, NULL);
            if (clen == (size_t)-1 || clen == (size_t)-2 ||
                clen == 0)
                errx(1, "illegal sequence");
            is_octal = 0;
            s->lastch = wch;
            s->str += clen;
            break;
        }

        /* We can start a range at any time. */
        if (s->str[0] == '-' && genrange(s, is_octal))
            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 CCLASS:
    case CCLASS_UPPER:
    case CCLASS_LOWER:
        s->cnt++;
        ch = nextwctype(s->lastch, s->cclass);
        if (ch == -1) {
            s->state = NORMAL;
            return (next(s));
        }
        s->lastch = ch;
        return (1);
    case SET:
        if ((ch = s->set[s->cnt++]) == OOBCH) {
            s->state = NORMAL;
            return (next(s));
        }
        s->lastch = ch;
        return (1);
    default:
        return (0);
    }
    /* NOTREACHED */
}

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

    switch (s->str[1]) {
    case ':':               /* "[:class:]" */
        if ((p = strchr(s->str + 2, ']')) == NULL)
            return (0);
        if (*(p - 1) != ':' || p - s->str < 4)
            goto repeat;
        *(p - 1) = '\0';
        s->str += 2;
        genclass(s);
        s->str = p + 1;
        return (1);
    case '=':               /* "[=equiv=]" */
        if ((p = strchr(s->str + 3, ']')) == NULL)
            return (0);
        if (*(p - 1) != '=' || p - s->str < 4)
            goto repeat;
        s->str += 2;
        genequiv(s);
        return (1);
    default:                /* "[\###*n]" or "[#*n]" */
    repeat:
        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 */
}

static void
genclass(s)
    STR *s;
{

    if ((s->cclass = wctype(s->str)) == 0)
        errx(1, "unknown class %s", s->str);
    s->cnt = 0;
    s->lastch = -1;     /* incremented before check in next() */
    if (strcmp(s->str, "upper") == 0)
        s->state = CCLASS_UPPER;
    else if (strcmp(s->str, "lower") == 0)
        s->state = CCLASS_LOWER;
    else
        s->state = CCLASS;
}

static void
genequiv(s)
    STR *s;
{
    int i, p, pri;
    char src[2], dst[3];
    size_t clen;
    wchar_t wc;

    if (*s->str == '\\') {
        s->equiv[0] = backslash(s, NULL);
        if (*s->str != '=')
            errx(1, "misplaced equivalence equals sign");
        s->str += 2;
    } else {
        clen = mbrtowc(&wc, s->str, MB_LEN_MAX, NULL);
        if (clen == (size_t)-1 || clen == (size_t)-2 || clen == 0) {
            errno = EILSEQ;
            err(1, NULL);
        }
        s->equiv[0] = wc;
        if (s->str[clen] != '=')
            errx(1, "misplaced equivalence equals sign");
        s->str += clen + 2;
    }

    /*
     * Calculate the set of all characters in the same equivalence class
     * as the specified character (they will have the same primary
     * collation weights).
     * XXX Knows too much about how strxfrm() is implemented. Assumes
     * it fills the string with primary collation weight bytes. Only one-
     * to-one mappings are supported.
     * XXX Equivalence classes not supported in multibyte locales.
     */
    src[0] = (char)s->equiv[0];
    src[1] = '\0';
    if (MB_CUR_MAX == 1 && strxfrm(dst, src, sizeof (dst)) == 1) {
        pri = (unsigned char)*dst;
        for (p = 1, i = 1; i < NCHARS_SB; i++) {
            *src = i;
            if (strxfrm(dst, src, sizeof (dst)) == 1 && pri &&
                pri == (unsigned char)*dst)
                s->equiv[p++] = i;
        }
        s->equiv[p] = OOBCH;
    }

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

static int
genrange(STR *s, int was_octal)
{
    int stopval, octal;
    char *savestart;
    int n, cnt, *p;
    size_t clen;
    wchar_t wc;

    octal = 0;
    savestart = s->str;
    if (*++s->str == '\\')
        stopval = backslash(s, &octal);
    else {
        clen = mbrtowc(&wc, s->str, MB_LEN_MAX, NULL);
        if (clen == (size_t)-1 || clen == (size_t)-2) {
            errno = EILSEQ;
            err(1, NULL);
        }
        stopval = wc;
        s->str += clen;
    }
    /*
     * XXX Characters are not ordered according to collating sequence in
     * multibyte locales.
     */
    if (octal || was_octal || MB_CUR_MAX > 1) {
        if (stopval < s->lastch) {
            s->str = savestart;
            return (0);
        }
        s->cnt = stopval - s->lastch + 1;
        s->state = RANGE;
        --s->lastch;
        return (1);
    }
    if (charcoll((const void *)&stopval, (const void *)&(s->lastch)) < 0) {
        s->str = savestart;
        return (0);
    }
    p = malloc((NCHARS_SB + 1) * sizeof (int));
    if ((s->set = (void *)p) == NULL)
        err(1, "genrange() malloc");
    for (cnt = 0; cnt < NCHARS_SB; cnt++)
        if (charcoll((const void *)&cnt, (const void *)&(s->lastch)) >=
            0 &&
            charcoll((const void *)&cnt, (const void *)&stopval) <= 0)
            *p++ = cnt;
    *p = OOBCH;
    n = (int *)p - (int *)s->set;

    s->cnt = 0;
    s->state = SET;
    if (n > 1)
        qsort(s->set, n, sizeof (*(s->set)), charcoll);
    return (1);
}

static void
genseq(s)
    STR *s;
{
    char *ep;
    wchar_t wc;
    size_t clen;

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

    if (*s->str == '\\')
        s->lastch = backslash(s, NULL);
    else {
        clen = mbrtowc(&wc, s->str, MB_LEN_MAX, NULL);
        if (clen == (size_t)-1 || clen == (size_t)-2) {
            errno = EILSEQ;
            err(1, NULL);
        }
        s->lastch = wc;
        s->str += clen;
    }
    if (*s->str != '*')
        errx(1, "misplaced sequence asterisk");

    switch (*++s->str) {
    case '\\':
        s->cnt = backslash(s, NULL);
        break;
    case ']':
        s->cnt = 0;
        ++s->str;
        break;
    default:
        if (isdigit((uchar_t)*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(STR *s, int *is_octal)
{
    int ch, cnt, val;

    if (is_octal != NULL)
        *is_octal = 0;
    for (cnt = val = 0; ; ) {
        ch = (uchar_t)*++s->str;
        if (!isdigit(ch) || ch > '7')
            break;
        val = val * 8 + ch - '0';
        if (++cnt == 3) {
            ++s->str;
            break;
        }
    }
    if (cnt) {
        if (is_octal != NULL)
            *is_octal = 1;
        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);
    }
}