path: root/lib/ephy-string.c

/*
 *  Copyright (C) 2002 Marco Pesenti Gritti
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2, or (at your option)
 *  any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

#include "ephy-string.h"

#include <string.h>
#include <glib.h>
#include <libgnome/libgnome.h>
#include <libgnome/gnome-i18n.h>
#include <libgnomevfs/gnome-vfs-mime.h>
#include <libxml/parser.h>

#define ELLIPSIS "\xe2\x80\xa6"

/**
 * ephy_string_shorten: returns a newly allocated shortened version of str.
 * The input must be valid utf-8.
 * @str: the string to shorten
 * @target_length: the length of the shortened string (in characters)
 *
 * FIXME: this function is a big mess. While it is utf-8 safe now,
 * it can still split a sequence of combining characters
 */
gchar *
ephy_string_shorten (const gchar *str, gint target_length)
{
    gchar *new_str;
    glong actual_length;
    gulong bytes;

    if (!str) return NULL;

    actual_length = g_utf8_strlen (str, -1);

    /* if the string is already short enough, or if it's too short for
     * us to shorten it, return a new copy */
    if (actual_length <= target_length) return g_strdup (str);

    /* create string */
    bytes = GPOINTER_TO_UINT (g_utf8_offset_to_pointer (str, target_length - 1) - str);
    
    new_str = g_new0 (gchar, bytes + strlen(ELLIPSIS) + 1);
    
    strncpy (new_str, str, bytes);
    strncpy (new_str + bytes, ELLIPSIS, strlen (ELLIPSIS));

    return new_str;
}

char *
ephy_string_double_underscores (const char *string)
{
        int underscores;
        const char *p;
        char *q;
        char *escaped;

        if (string == NULL) {
                return NULL;
        }

        underscores = 0;
        for (p = string; *p != '\0'; p++) {
                underscores += (*p == '_');
        }

        if (underscores == 0) {
                return g_strdup (string);
        }

        escaped = g_new (char, strlen (string) + underscores + 1);
        for (p = string, q = escaped; *p != '\0'; p++, q++) {
                /* Add an extra underscore. */
                if (*p == '_') {
                        *q++ = '_';
                }
                *q = *p;
        }
        *q = '\0';

        return escaped;
}

/**
 * ephy_string_store_time_in_string:
 * NOTE: str must be at least 256 chars long
 */
void
ephy_string_store_time_in_string (GDate *t, gchar *str, const char *format)
{
    int length;

    if (t > 0)
    {
        /* format into string */
        /* this is used whenever a brief date is needed, like
         * in the history (for last visited, first time visited) */
        length = g_date_strftime (str, 255,
                          format ? format : _("%Y-%m-%d"), t);
        str[length] = '\0';
    }
    else
    {
        str[0] = '\0';
    }
}

/**
 * ephy_string_time_to_string:
 */
gchar *
ephy_string_time_to_string (GDate *t,
                const char *format)
{
    gchar str[256];

    /* write into stack string */
    ephy_string_store_time_in_string (t, str, format);

    /* copy in heap and return */
    return g_strdup (str);
}

gboolean
ephy_str_to_int (const char *string, gulong *integer)
{
    gulong result;
    char *parse_end;

    /* Check for the case of an empty string. */
    if (string == NULL || *string == '\0') {
        return FALSE;
    }

    /* Call the standard library routine to do the conversion. */
    errno = 0;
    result = strtol (string, &parse_end, 0);

    /* Check that the result is in range. */
    if ((result == G_MINLONG || result == G_MAXLONG) && errno == ERANGE) {
        return FALSE;
    }

    /* Check that all the trailing characters are spaces. */
    while (*parse_end != '\0') {
        if (!g_ascii_isspace (*parse_end++)) {
            return FALSE;
        }
    }

    /* Return the result. */
    *integer = result;
    return TRUE;
}

/**
 * ephy_str_strip_chr:
 * Remove all occurrences of a character from a string.
 *
 * @source: The string to be stripped.
 * @remove_this: The char to remove from @source
 *
 * Return value: A copy of @source, after removing all occurrences
 * of @remove_this.
 */
char *
ephy_str_strip_chr (const char *source, char remove_this)
{
    char *result, *out;
    const char *in;

        if (source == NULL) {
        return NULL;
    }

    result = g_new (char, strlen (source) + 1);
    in = source;
    out = result;
    do {
        if (*in != remove_this) {
            *out++ = *in;
        }
    } while (*in++ != '\0');

        return result;
}

int
ephy_strcasecmp (const char *string_a, const char *string_b)
{
        return g_ascii_strcasecmp (string_a == NULL ? "" : string_a,
                                   string_b == NULL ? "" : string_b);
}

int
ephy_strcasecmp_compare_func (gconstpointer string_a, gconstpointer string_b)
{
        return ephy_strcasecmp ((const char *) string_a,
                   (const char *) string_b);
}

/**
 * like strpbrk but ignores chars preceded by slashes, unless the
 * slash is also preceded by a slash unless that later slash is
 * preceded by another slash... ;-)
 */
static char *
ephy_strpbrk_unescaped (const char *s, const char *accept)
{
    gchar *ret = strpbrk (s, accept);

    if (!ret || ret == s || *(ret - 1) != '\\')
    {
        return ret;
    }
    else
    {
        gchar *c = ret - 1;
        g_assert (*c == '\\');

        while (c >= s && *c == '\\') c--;

        if ((ret - c) % 2 == 0)
        {
            return ephy_strpbrk_unescaped (ret + 1, accept);
        }
        else
        {
            return ret;
        }
    }
}

/**
 * like strstr but supports quoting, ignoring matches inside quoted text
 */
static char *
ephy_strstr_with_quotes (const char *haystack, const char *needle,
             const char *quotes)
{
    gchar *quot = ephy_strpbrk_unescaped (haystack, quotes);
    gchar *ret = strstr (haystack, needle);

    if (!quot || !ret || ret < quot)
    {
        return ret;
    }

    quot = ephy_strpbrk_unescaped (quot + 1, quotes);

    if (quot)
    {
        return ephy_strstr_with_quotes (quot + 1, needle, quotes);
    }
    else
    {
        return NULL;
    }
}

/**
 * like strpbrk but supports quoting, ignoring matches inside quoted text
 */
static char *
ephy_strpbrk_with_quotes (const char *haystack, const char *needles,
              const char *quotes)
{
    gchar *quot = ephy_strpbrk_unescaped (haystack, quotes);
    gchar *ret = strpbrk (haystack, needles);

    if (!quot || !ret || ret < quot)
    {
        return ret;
    }

    quot = ephy_strpbrk_unescaped (quot + 1, quotes);

    if (quot)
    {
        return ephy_strpbrk_with_quotes (quot + 1, needles, quotes);
    }
    else
    {
        return NULL;
    }
}

/**
 * Like g_strsplit, but does not split tokens betwen quotes. Ignores
 * quotes preceded by '\'.
 */
gchar **
ephy_strsplit_with_quotes (const gchar *string,
               const gchar *delimiter,
               gint max_tokens,
               const gchar *quotes)
{
    GSList *string_list = NULL, *slist;
    gchar **str_array, *s;
    guint n = 0;
    const gchar *remainder;

    g_return_val_if_fail (string != NULL, NULL);
    g_return_val_if_fail (delimiter != NULL, NULL);
    g_return_val_if_fail (delimiter[0] != '\0', NULL);

    if (quotes == NULL)
    {
        return g_strsplit (string, delimiter, max_tokens);
    }

    if (max_tokens < 1)
    {
        max_tokens = G_MAXINT;
    }

    remainder = string;
    s = ephy_strstr_with_quotes (remainder, delimiter, quotes);
    if (s)
    {
        gsize delimiter_len = strlen (delimiter);

        while (--max_tokens && s)
        {
            gsize len;
            gchar *new_string;

            len = s - remainder;
            new_string = g_new (gchar, len + 1);
            strncpy (new_string, remainder, len);
            new_string[len] = 0;
            string_list = g_slist_prepend (string_list, new_string);
            n++;
            remainder = s + delimiter_len;
            s = ephy_strstr_with_quotes (remainder, delimiter, quotes);
        }
    }
    if (*string)
    {
        n++;
        string_list = g_slist_prepend (string_list, g_strdup (remainder));
    }

    str_array = g_new (gchar*, n + 1);

    str_array[n--] = NULL;
    for (slist = string_list; slist; slist = slist->next)
    {
        str_array[n--] = slist->data;
    }

    g_slist_free (string_list);

    return str_array;
}

/**
 * like ephy_strsplit_with_quotes, but matches any char in 'delimiters' as delimiter
 * and does not return empty tokens
 */
gchar **
ephy_strsplit_multiple_delimiters_with_quotes (const gchar *string,
                           const gchar *delimiters,
                           gint max_tokens,
                           const gchar *quotes)
{
    GSList *string_list = NULL, *slist;
    gchar **str_array, *s;
    guint n = 0;
    const gchar *remainder;

    g_return_val_if_fail (string != NULL, NULL);
    g_return_val_if_fail (delimiters != NULL, NULL);
    g_return_val_if_fail (delimiters[0] != '\0', NULL);

    if (quotes == NULL)
    {
        quotes = "";
    }

    if (max_tokens < 1)
    {
        max_tokens = G_MAXINT;
    }

    remainder = string;
    s = ephy_strpbrk_with_quotes (remainder, delimiters, quotes);
    if (s)
    {
        const gsize delimiter_len = 1; /* only chars */

        while (--max_tokens && s)
        {
            gsize len;
            gchar *new_string;

            len = s - remainder;
            if (len > 0) /* ignore empty strings */
            {
                new_string = g_new (gchar, len + 1);
                strncpy (new_string, remainder, len);
                new_string[len] = 0;
                string_list = g_slist_prepend (string_list, new_string);
                n++;
            }
            remainder = s + delimiter_len;
            s = ephy_strpbrk_with_quotes (remainder, delimiters, quotes);
        }
    }
    if (*string)
    {
        n++;
        string_list = g_slist_prepend (string_list, g_strdup (remainder));
    }

    str_array = g_new (gchar*, n + 1);

    str_array[n--] = NULL;
    for (slist = string_list; slist; slist = slist->next)
    {
        str_array[n--] = slist->data;
    }

    g_slist_free (string_list);

    return str_array;
}

char *
ephy_str_replace_substring (const char *string,
                const char *substring,
                const char *replacement)
{
    int substring_length, replacement_length, result_length, remaining_length;
    const char *p, *substring_position;
    char *result, *result_position;

    g_return_val_if_fail (substring != NULL, g_strdup (string));
    g_return_val_if_fail (substring[0] != '\0', g_strdup (string));

    if (string == NULL)
    {
        return NULL;
    }

    substring_length = strlen (substring);
    replacement_length = replacement == NULL ? 0 : strlen (replacement);

    result_length = strlen (string);
    for (p = string; ; p = substring_position + substring_length)
    {
        substring_position = strstr (p, substring);
        if (substring_position == NULL)
        {
            break;
        }
        result_length += replacement_length - substring_length;
    }

    result = g_malloc (result_length + 1);

    result_position = result;
    for (p = string; ; p = substring_position + substring_length)
    {
        substring_position = strstr (p, substring);
        if (substring_position == NULL)
        {
            remaining_length = strlen (p);
            memcpy (result_position, p, remaining_length);
            result_position += remaining_length;
            break;
        }
        memcpy (result_position, p, substring_position - p);
        result_position += substring_position - p;
        memcpy (result_position, replacement, replacement_length);
        result_position += replacement_length;
    }
    g_assert (result_position - result == result_length);
    result_position[0] = '\0';

    return result;
}