strings/apr_strtok.c

/* Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifdef HAVE_STDDEF_H
#include <stddef.h>        /* for NULL */
#endif

#include "apr.h"
#include "apr_strings.h"

#define APR_WANT_STRFUNC   /* for strchr() */
#include "apr_want.h"

APR_DECLARE(char *) apr_strtok(char *str, const char *sep, char **last)
{
    char *token;

    if (!str)           /* subsequent call */
        str = *last;    /* start where we left off */

    /* skip characters in sep (will terminate at '\0') */
    while (*str && strchr(sep, *str))
        ++str;

    if (!*str)          /* no more tokens */
        return NULL;

    token = str;

    /* skip valid token characters to terminate token and
     * prepare for the next call (will terminate at '\0)
     */
    *last = token + 1;
    while (**last && !strchr(sep, **last))
        ++*last;

    if (**last) {
        **last = '\0';
        ++*last;
    }

    return token;
}

APR_DECLARE(char *) apr_strqtok(char *str, const char *sep, char **last)
{
    char *token;
    apr_size_t rewind = 0;
    char c, q = 0, s = 0;

    if (!str) {         /* subsequent call */
        str = *last;    /* start where we left off */
    }

    /* skip characters in sep (will terminate at '\0') */
    while (*str && strchr(sep, *str)) {
        ++str;
    }

    if (!*str) {        /* no more tokens */
        return NULL;
    }

    token = str;

    /* skip quoted sections */
    while ((c = *str)) {

        if (!q) {
            if ('\'' == c) {
                q = '\'';
                rewind++;
            }
            else if ('\"' == c) {
                q = '\"';
                rewind++;
            }
            else if (strchr(sep, c)) {
                break;
            }
            else if (rewind) {
                str[-rewind] = c;
            }
        }
        else {
            if (!s) {
                if ('\\' == c) {
                    s = c;
                    rewind++;
                }
                else if (!s && q == c) {
                    rewind++;
                    q = 0;
                }
                else if (rewind) {
                    str[-rewind] = c;
                }
            }
            else {
                s = 0;
                if (rewind) {
                    str[-rewind] = c;
                }
            }
        }

        str++;
    }

    if (rewind) {
        str[-rewind] = '\0';
    }

    /* prepare for the next call (will terminate at '\0)
     */
    *last = str;

    if (**last) {
        **last = '\0';
        ++*last;
    }

    return token;
}