bin/ed/re.c

/* re.c: This file contains the regular expression interface routines for
   the ed line editor. */
/*-
 * Copyright (c) 1993 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley
 * by Andrew Moore, Talke Studio.
 *
 * 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.
 */

#ifndef lint
static char sccsid[] = "@(#)re.c        5.5 (Berkeley) 3/28/93";
#endif /* not lint */

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

#include "ed.h"

extern char *lhbuf;
extern int lhbufsz;
extern char *ibufp;
extern int ibufsz;
extern int patlock;

char errmsg[MAXFNAME + 40] = "";

/* optpat: return pointer to compiled pattern from command buffer */
pattern_t *
optpat()
{
        static pattern_t *exp = NULL;

        char *exps;
        char delim;
        int n;

        if ((delim = *ibufp) == '\n') {
                if (!exp) sprintf(errmsg, "no previous pattern");
                return exp;
        } else if (delim == ' ' || *++ibufp == '\n') {
                sprintf(errmsg, "invalid pattern delimiter");
                return NULL;
        } else if (*ibufp == delim) {
                sprintf(errmsg, "no previous pattern");
                return exp;
        } else if ((exps = getlhs(delim)) == NULL)
                return NULL;
        /* buffer alloc'd && not reserved */
        if (exp && !patlock)
                regfree(exp);
        else if ((exp = (pattern_t *) malloc(sizeof(pattern_t))) == NULL) {
                fprintf(stderr, "%s\n", strerror(errno));
                sprintf(errmsg, "out of memory");
                return NULL;
        }
        patlock = 0;
#ifdef GNU_REGEX
        /* initialize pattern buffer */
        exp->buffer = NULL;
        exp->allocated = 0L;
        exp->fastmap = 0;               /* not used by GNU regex after 0.12 */
        exp->translate = 0;
#endif
        if (n = regcomp(exp, exps, 0)) {
                regerror(n, exp, errmsg, sizeof errmsg);
                return NULL;
        }
        return exp;
}


extern int isbinary;

/* getlhs: copy a pattern string from the command buffer; return pointer
   to the copy */
char *
getlhs(delim)
        int delim;
{
        char *nd;
        int len;

        for (nd = ibufp; *nd != delim && *nd != '\n'; nd++)
                switch (*nd) {
                default:
                        break;
                case '[':
                        if ((nd = ccl(++nd)) == NULL) {
                                sprintf(errmsg, "unbalanced brackets ([])");
                                return NULL;
                        }
                        break;
                case '\\':
                        if (*++nd == '\n') {
                                sprintf(errmsg, "trailing backslash (\\)");
                                return NULL;
                        }
                        break;
                }
        len = nd - ibufp;
        CKBUF(lhbuf, lhbufsz, len + 1, NULL);
        memcpy(lhbuf, ibufp, len);
        lhbuf[len] = '\0';
        ibufp = nd;
        return (isbinary) ? nultonl(lhbuf, len) : lhbuf;
}


/* ccl: expand a POSIX character class */
char *
ccl(s)
        char *s;
{
        int c, d;

        if (*s == '^')
                s++;
        if (*s == ']')
                s++;
        for (; *s != ']' && *s != '\n'; s++)
                if (*s == '[' && ((d = *(s+1)) == '.' || d == ':' || d == '='))
                        for (s++, c = *++s; *s != ']' || c != d; s++)
                                if ((c = *s) == '\n')
                                        return NULL;
        return  (*s == ']') ? s : NULL;
}