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/* GIO - GLib Input, Output and Streaming Library
*
* Copyright (C) 2006-2007 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General
* Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
*
* Author: Alexander Larsson <alexl@redhat.com>
*/
#include "config.h"
#include "gurifuncs.h"
#include <glib/gstrfuncs.h>
#include <glib/gmessages.h>
#include <glib/gstring.h>
#include <glib/gmem.h>
#include <string.h>
#include "config.h"
/**
* SECTION:gurifuncs
* @title: URI Functions
* @short_description: manipulating URIs
*
* Functions for manipulating Universal Resource Identifiers (URIs) as
* defined by
* [RFC 3986](http://www.ietf.org/rfc/rfc3986.txt).
* It is highly recommended that you have read and
* understand RFC 3986 for understanding this API.
*/
static int
unescape_character (const char *scanner)
{
int first_digit;
int second_digit;
first_digit = g_ascii_xdigit_value (*scanner++);
if (first_digit < 0)
return -1;
second_digit = g_ascii_xdigit_value (*scanner++);
if (second_digit < 0)
return -1;
return (first_digit << 4) | second_digit;
}
/**
* g_uri_unescape_segment:
* @escaped_string: (nullable): A string, may be %NULL
* @escaped_string_end: (nullable): Pointer to end of @escaped_string, may be %NULL
* @illegal_characters: (nullable): An optional string of illegal characters not to be allowed, may be %NULL
*
* Unescapes a segment of an escaped string.
*
* If any of the characters in @illegal_characters or the character zero appears
* as an escaped character in @escaped_string then that is an error and %NULL
* will be returned. This is useful it you want to avoid for instance having a
* slash being expanded in an escaped path element, which might confuse pathname
* handling.
*
* Returns: an unescaped version of @escaped_string or %NULL on error.
* The returned string should be freed when no longer needed. As a
* special case if %NULL is given for @escaped_string, this function
* will return %NULL.
*
* Since: 2.16
**/
char *
g_uri_unescape_segment (const char *escaped_string,
const char *escaped_string_end,
const char *illegal_characters)
{
const char *in;
char *out, *result;
gint character;
if (escaped_string == NULL)
return NULL;
if (escaped_string_end == NULL)
escaped_string_end = escaped_string + strlen (escaped_string);
result = g_malloc (escaped_string_end - escaped_string + 1);
out = result;
for (in = escaped_string; in < escaped_string_end; in++)
{
character = *in;
if (*in == '%')
{
in++;
if (escaped_string_end - in < 2)
{
/* Invalid escaped char (to short) */
g_free (result);
return NULL;
}
character = unescape_character (in);
/* Check for an illegal character. We consider '\0' illegal here. */
if (character <= 0 ||
(illegal_characters != NULL &&
strchr (illegal_characters, (char)character) != NULL))
{
g_free (result);
return NULL;
}
in++; /* The other char will be eaten in the loop header */
}
*out++ = (char)character;
}
*out = '\0';
return result;
}
/**
* g_uri_unescape_string:
* @escaped_string: an escaped string to be unescaped.
* @illegal_characters: (nullable): a string of illegal characters not to be
* allowed, or %NULL.
*
* Unescapes a whole escaped string.
*
* If any of the characters in @illegal_characters or the character zero appears
* as an escaped character in @escaped_string then that is an error and %NULL
* will be returned. This is useful it you want to avoid for instance having a
* slash being expanded in an escaped path element, which might confuse pathname
* handling.
*
* Returns: an unescaped version of @escaped_string. The returned string
* should be freed when no longer needed.
*
* Since: 2.16
**/
char *
g_uri_unescape_string (const char *escaped_string,
const char *illegal_characters)
{
return g_uri_unescape_segment (escaped_string, NULL, illegal_characters);
}
/**
* g_uri_parse_scheme:
* @uri: a valid URI.
*
* Gets the scheme portion of a URI string. RFC 3986 decodes the scheme as:
* |[
* URI = scheme ":" hier-part [ "?" query ] [ "#" fragment ]
* ]|
* Common schemes include "file", "http", "svn+ssh", etc.
*
* Returns: The "Scheme" component of the URI, or %NULL on error.
* The returned string should be freed when no longer needed.
*
* Since: 2.16
**/
char *
g_uri_parse_scheme (const char *uri)
{
const char *p;
char c;
g_return_val_if_fail (uri != NULL, NULL);
/* From RFC 3986 Decodes:
* URI = scheme ":" hier-part [ "?" query ] [ "#" fragment ]
*/
p = uri;
/* Decode scheme:
scheme = ALPHA *( ALPHA / DIGIT / "+" / "-" / "." )
*/
if (!g_ascii_isalpha (*p))
return NULL;
while (1)
{
c = *p++;
if (c == ':')
break;
if (!(g_ascii_isalnum(c) ||
c == '+' ||
c == '-' ||
c == '.'))
return NULL;
}
return g_strndup (uri, p - uri - 1);
}
/**
* g_uri_escape_string:
* @unescaped: the unescaped input string.
* @reserved_chars_allowed: (nullable): a string of reserved characters that
* are allowed to be used, or %NULL.
* @allow_utf8: %TRUE if the result can include UTF-8 characters.
*
* Escapes a string for use in a URI.
*
* Normally all characters that are not "unreserved" (i.e. ASCII alphanumerical
* characters plus dash, dot, underscore and tilde) are escaped.
* But if you specify characters in @reserved_chars_allowed they are not
* escaped. This is useful for the "reserved" characters in the URI
* specification, since those are allowed unescaped in some portions of
* a URI.
*
* Returns: an escaped version of @unescaped. The returned string should be
* freed when no longer needed.
*
* Since: 2.16
**/
char *
g_uri_escape_string (const char *unescaped,
const char *reserved_chars_allowed,
gboolean allow_utf8)
{
GString *s;
g_return_val_if_fail (unescaped != NULL, NULL);
s = g_string_sized_new (strlen (unescaped) + 10);
g_string_append_uri_escaped (s, unescaped, reserved_chars_allowed, allow_utf8);
return g_string_free (s, FALSE);
}