uri.c.svn-base

这是一个用于解析xml文件的类库。使用这个类库

    }
    if (ret != 0)
	return(ret);
    if (*cur == '?') {
	cur++;
	ret = xmlParseURIQuery(uri, &cur);
	if (ret != 0)
	    return(ret);
    }
    *str = cur;
    return(0);
}

/**
 * xmlParseAbsoluteURI:
 * @uri:  pointer to an URI structure
 * @str:  pointer to the string to analyze
 *
 * Parse an URI reference string and fills in the appropriate fields
 * of the @uri structure
 * 
 * absoluteURI   = scheme ":" ( hier_part | opaque_part )
 *
 * Returns 0 or the error code
 */
static int
xmlParseAbsoluteURI(xmlURIPtr uri, const char **str) {
    int ret;
    const char *cur;

    if (str == NULL)
	return(-1);
    
    cur = *str;

    ret = xmlParseURIScheme(uri, str);
    if (ret != 0) return(ret);
    if (**str != ':') {
	*str = cur;
	return(1);
    }
    (*str)++;
    if (**str == '/')
	return(xmlParseURIHierPart(uri, str));
    return(xmlParseURIOpaquePart(uri, str));
}

/**
 * xmlParseRelativeURI:
 * @uri:  pointer to an URI structure
 * @str:  pointer to the string to analyze
 *
 * Parse an relative URI string and fills in the appropriate fields
 * of the @uri structure
 * 
 * relativeURI = ( net_path | abs_path | rel_path ) [ "?" query ]
 * abs_path = "/"  path_segments
 * net_path = "//" authority [ abs_path ]
 * rel_path = rel_segment [ abs_path ]
 *
 * Returns 0 or the error code
 */
static int
xmlParseRelativeURI(xmlURIPtr uri, const char **str) {
    int ret = 0;
    const char *cur;

    if (str == NULL)
	return(-1);
    
    cur = *str;
    if ((cur[0] == '/') && (cur[1] == '/')) {
	cur += 2;
	ret = xmlParseURIAuthority(uri, &cur);
	if (ret != 0)
	    return(ret);
	if (cur[0] == '/') {
	    cur++;
	    ret = xmlParseURIPathSegments(uri, &cur, 1);
	}
    } else if (cur[0] == '/') {
	cur++;
	ret = xmlParseURIPathSegments(uri, &cur, 1);
    } else if (cur[0] != '#' && cur[0] != '?') {
	ret = xmlParseURIRelSegment(uri, &cur);
	if (ret != 0)
	    return(ret);
	if (cur[0] == '/') {
	    cur++;
	    ret = xmlParseURIPathSegments(uri, &cur, 1);
	}
    }
    if (ret != 0)
	return(ret);
    if (*cur == '?') {
	cur++;
	ret = xmlParseURIQuery(uri, &cur);
	if (ret != 0)
	    return(ret);
    }
    *str = cur;
    return(ret);
}

/**
 * xmlParseURIReference:
 * @uri:  pointer to an URI structure
 * @str:  the string to analyze
 *
 * Parse an URI reference string and fills in the appropriate fields
 * of the @uri structure
 * 
 * URI-reference = [ absoluteURI | relativeURI ] [ "#" fragment ]
 *
 * Returns 0 or the error code
 */
int
xmlParseURIReference(xmlURIPtr uri, const char *str) {
    int ret;
    const char *tmp = str;

    if (str == NULL)
	return(-1);
    xmlCleanURI(uri);

    /*
     * Try first to parse absolute refs, then fallback to relative if
     * it fails.
     */
    ret = xmlParseAbsoluteURI(uri, &str);
    if (ret != 0) {
	xmlCleanURI(uri);
	str = tmp;
        ret = xmlParseRelativeURI(uri, &str);
    }
    if (ret != 0) {
	xmlCleanURI(uri);
	return(ret);
    }

    if (*str == '#') {
	str++;
	ret = xmlParseURIFragment(uri, &str);
	if (ret != 0) return(ret);
    }
    if (*str != 0) {
	xmlCleanURI(uri);
	return(1);
    }
    return(0);
}

/**
 * xmlParseURI:
 * @str:  the URI string to analyze
 *
 * Parse an URI 
 * 
 * URI-reference = [ absoluteURI | relativeURI ] [ "#" fragment ]
 *
 * Returns a newly build xmlURIPtr or NULL in case of error
 */
xmlURIPtr
xmlParseURI(const char *str) {
    xmlURIPtr uri;
    int ret;

    if (str == NULL)
	return(NULL);
    uri = xmlCreateURI();
    if (uri != NULL) {
	ret = xmlParseURIReference(uri, str);
        if (ret) {
	    xmlFreeURI(uri);
	    return(NULL);
	}
    }
    return(uri);
}

/************************************************************************
 *									*
 *			Public functions				*
 *									*
 ************************************************************************/

/**
 * xmlBuildURI:
 * @URI:  the URI instance found in the document
 * @base:  the base value
 *
 * Computes he final URI of the reference done by checking that
 * the given URI is valid, and building the final URI using the
 * base URI. This is processed according to section 5.2 of the 
 * RFC 2396
 *
 * 5.2. Resolving Relative References to Absolute Form
 *
 * Returns a new URI string (to be freed by the caller) or NULL in case
 *         of error.
 */
xmlChar *
xmlBuildURI(const xmlChar *URI, const xmlChar *base) {
    xmlChar *val = NULL;
    int ret, len, indx, cur, out;
    xmlURIPtr ref = NULL;
    xmlURIPtr bas = NULL;
    xmlURIPtr res = NULL;

    /*
     * 1) The URI reference is parsed into the potential four components and
     *    fragment identifier, as described in Section 4.3.
     *
     *    NOTE that a completely empty URI is treated by modern browsers
     *    as a reference to "." rather than as a synonym for the current
     *    URI.  Should we do that here?
     */
    if (URI == NULL) 
	ret = -1;
    else {
	if (*URI) {
	    ref = xmlCreateURI();
	    if (ref == NULL)
		goto done;
	    ret = xmlParseURIReference(ref, (const char *) URI);
	}
	else
	    ret = 0;
    }
    if (ret != 0)
	goto done;
    if ((ref != NULL) && (ref->scheme != NULL)) {
	/*
	 * The URI is absolute don't modify.
	 */
	val = xmlStrdup(URI);
	goto done;
    }
    if (base == NULL)
	ret = -1;
    else {
	bas = xmlCreateURI();
	if (bas == NULL)
	    goto done;
	ret = xmlParseURIReference(bas, (const char *) base);
    }
    if (ret != 0) {
	if (ref)
	    val = xmlSaveUri(ref);
	goto done;
    }
    if (ref == NULL) {
	/*
	 * the base fragment must be ignored
	 */
	if (bas->fragment != NULL) {
	    xmlFree(bas->fragment);
	    bas->fragment = NULL;
	}
	val = xmlSaveUri(bas);
	goto done;
    }

    /*
     * 2) If the path component is empty and the scheme, authority, and
     *    query components are undefined, then it is a reference to the
     *    current document and we are done.  Otherwise, the reference URI's
     *    query and fragment components are defined as found (or not found)
     *    within the URI reference and not inherited from the base URI.
     *
     *    NOTE that in modern browsers, the parsing differs from the above
     *    in the following aspect:  the query component is allowed to be
     *    defined while still treating this as a reference to the current
     *    document.
     */
    res = xmlCreateURI();
    if (res == NULL)
	goto done;
    if ((ref->scheme == NULL) && (ref->path == NULL) &&
	((ref->authority == NULL) && (ref->server == NULL))) {
	if (bas->scheme != NULL)
	    res->scheme = xmlMemStrdup(bas->scheme);
	if (bas->authority != NULL)
	    res->authority = xmlMemStrdup(bas->authority);
	else if (bas->server != NULL) {
	    res->server = xmlMemStrdup(bas->server);
	    if (bas->user != NULL)
		res->user = xmlMemStrdup(bas->user);
	    res->port = bas->port;		
	}
	if (bas->path != NULL)
	    res->path = xmlMemStrdup(bas->path);
	if (ref->query != NULL)
	    res->query = xmlMemStrdup(ref->query);
	else if (bas->query != NULL)
	    res->query = xmlMemStrdup(bas->query);
	if (ref->fragment != NULL)
	    res->fragment = xmlMemStrdup(ref->fragment);
	goto step_7;
    }

    /*
     * 3) If the scheme component is defined, indicating that the reference
     *    starts with a scheme name, then the reference is interpreted as an
     *    absolute URI and we are done.  Otherwise, the reference URI's
     *    scheme is inherited from the base URI's scheme component.
     */
    if (ref->scheme != NULL) {
	val = xmlSaveUri(ref);
	goto done;
    }
    if (bas->scheme != NULL)
	res->scheme = xmlMemStrdup(bas->scheme);
 
    if (ref->query != NULL)
	res->query = xmlMemStrdup(ref->query);
    if (ref->fragment != NULL)
	res->fragment = xmlMemStrdup(ref->fragment);

    /*
     * 4) If the authority component is defined, then the reference is a
     *    network-path and we skip to step 7.  Otherwise, the reference
     *    URI's authority is inherited from the base URI's authority
     *    component, which will also be undefined if the URI scheme does not
     *    use an authority component.
     */
    if ((ref->authority != NULL) || (ref->server != NULL)) {
	if (ref->authority != NULL)
	    res->authority = xmlMemStrdup(ref->authority);
	else {
	    res->server = xmlMemStrdup(ref->server);
	    if (ref->user != NULL)
		res->user = xmlMemStrdup(ref->user);
            res->port = ref->port;		
	}
	if (ref->path != NULL)
	    res->path = xmlMemStrdup(ref->path);
	goto step_7;
    }
    if (bas->authority != NULL)
	res->authority = xmlMemStrdup(bas->authority);
    else if (bas->server != NULL) {
	res->server = xmlMemStrdup(bas->server);
	if (bas->user != NULL)
	    res->user = xmlMemStrdup(bas->user);
	res->port = bas->port;		
    }

    /*
     * 5) If the path component begins with a slash character ("/"), then
     *    the reference is an absolute-path and we skip to step 7.
     */
    if ((ref->path != NULL) && (ref->path[0] == '/')) {
	res->path = xmlMemStrdup(ref->path);
	goto step_7;
    }


    /*
     * 6) If this step is reached, then we are resolving a relative-path
     *    reference.  The relative path needs to be merged with the base
     *    URI's path.  Although there are many ways to do this, we will
     *    describe a simple method using a separate string buffer.
     *
     * Allocate a buffer large enough for the result string.
     */
    len = 2; /* extra / and 0 */
    if (ref->path != NULL)
	len += strlen(ref->path);
    if (bas->path != NULL)
	len += strlen(bas->path);
    res->path = (char *) xmlMallocAtomic(len);
    if (res->path == NULL) {
	xmlGenericError(xmlGenericErrorContext,
		"xmlBuildURI: out of memory\n");
	goto done;
    }
    res->path[0] = 0;

    /*
     * a) All but the last segment of the base URI's path component is
     *    copied to the buffer.  In other words, any characters after the
     *    last (right-most) slash character, if any, are excluded.
     */
    cur = 0;
    out = 0;
    if (bas->path != NULL) {
	while (bas->path[cur] != 0) {
	    while ((bas->path[cur] != 0) && (bas->path[cur] != '/'))
		cur++;
	    if (bas->path[cur] == 0)
		break;

	    cur++;
	    while (out < cur) {
		res->path[out] = bas->path[out];
		out++;
	    }
	}
    }
    res->path[out] = 0;

    /*
     * b) The reference's path component is appended to the buffer
     *    string.
     */
    if (ref->path != NULL && ref->path[0] != 0) {
	indx = 0;
	/*
	 * Ensure the path includes a '/'
	 */
	if ((out == 0) && (bas->server != NULL))
	    res->path[out++] = '/';
	while (ref->path[indx] != 0) {
	    res->path[out++] = ref->path[indx++];
	}
    }
    res->path[out] = 0;

    /*
     * Steps c) to h) are really path normalization steps
     */
    xmlNormalizeURIPath(res->path);

step_7:

    /*
     * 7) The resulting URI components, including any inherited from the
     *    base URI, are recombined to give the absolute form of the URI
     *    reference.
     */
    val = xmlSaveUri(res);

done:
    if (ref != NULL)
	xmlFreeURI(ref);
    if (bas != NULL)
	xmlFreeURI(bas);
    if (res != NULL)
	xmlFreeURI(res);
    return(val);
}

/**
 * xmlCanonicPath:
 * @path:  the resource locator in a filesystem notation
 *
 * Constructs a canonic path from the specified path. 
 *
 * Returns a new canonic path, or a duplicate of the path parameter if the 
 * construction fails. The caller is responsible for freeing the memory occupied
 * by the returned string. If there is insufficient memory available, or the 
 * argument is NULL, the function returns NULL.
 */
#define IS_WINDOWS_PATH(p) 					\
	((p != NULL) &&						\
	 (((p[0] >= 'a') && (p[0] <= 'z')) ||			\
	  ((p[0] >= 'A') && (p[0] <= 'Z'))) &&			\
	 (p[1] == ':') && ((p[2] == '/') || (p[2] == '\\')))
xmlChar*
xmlCanonicPath(const xmlChar *path)
{
#if defined(_WIN32) && !defined(__CYGWIN__)    
    int len = 0;
    int i = 0;
    xmlChar *p = NULL;
#endif
    xmlChar *ret;
    xmlURIPtr uri;

    if (path == NULL)
	return(NULL);
    if ((uri = xmlParseURI((const char *) path)) != NULL) {
	xmlFreeURI(uri);
	return xmlStrdup(path);
    }

    uri = xmlCreateURI();
    if (uri == NULL) {
        return(NULL);
    }

#if defined(_WIN32) && !defined(__CYGWIN__)    
    len = xmlStrlen(path);
    if ((len > 2) && IS_WINDOWS_PATH(path)) {
	uri->scheme = xmlStrdup(BAD_CAST "file");
	uri->path = xmlMallocAtomic(len + 2);
	uri->path[0] = '/';
	p = uri->path + 1;
	strncpy(p, path, len + 1);
    } else {
	uri->path = xmlStrdup(path);
	p = uri->path;
    }
    while (*p != '\0') {
	if (*p == '\\')
	    *p = '/';
	p++;
    }
#else
    uri->path = (char *) xmlStrdup((const xmlChar *) path);
#endif
    
    ret = xmlSaveUri(uri);
    xmlFreeURI(uri);
    return(ret);
}