readme

适用于嵌入式系统的XML解析库, 规模比libxml2小得多.

README - 2008-01-28
-------------------


INTRODUCTION

    This README file describes the Mini-XML library version 2.5.

    Mini-XML is a small XML parsing library that you can use to
    read XML and XML-like data files in your application without
    requiring large non-standard libraries.  Mini-XML only
    requires an ANSI C compatible compiler (GCC works, as do
    most vendors' ANSI C compilers) and a "make" program.

    Mini-XML provides the following functionality:

	- Reading of UTF-8 and UTF-16 and writing of UTF-8
	  encoded XML files and strings.
	- Data is stored in a linked-list tree structure,
	  preserving the XML data hierarchy.
	- Supports arbitrary element names, attributes, and
	  attribute values with no preset limits, just available
	  memory.
	- Supports integer, real, opaque ("cdata"), and text
	  data types in "leaf" nodes.
	- Functions for creating and managing trees of data.
	- "Find" and "walk" functions for easily locating and
	  navigating trees of data.

    Mini-XML doesn't do validation or other types of processing
    on the data based upon schema files or other sources of
    definition information.


BUILDING Mini-XML

    Mini-XML comes with an autoconf-based configure script; just
    type the following command to get things going:

        ./configure

    The default install prefix is /usr/local, which can be
    overridden using the --prefix option:

        ./configure --prefix=/foo

    Other configure options can be found using the --help
    option:

        ./configure --help

    Once you have configured the software, type "make" to do the
    build and run the test program to verify that things are
    working, as follows:

        make

    If you are using Mini-XML under Microsoft Windows with
    Visual C++, use the included project files in the "vcnet"
    subdirectory to build the library instead.


INSTALLING Mini-XML

    The "install" target will install Mini-XML in the lib and
    include directories:

        make install

    Once you have installed it, use the "-lmxml" option to link
    your application against it.


DOCUMENTATION

    The documentation is available in the "doc" subdirectory in
    the files "mxml.html" (HTML) and "mxml.pdf" (PDF). You can
    also look at the "testmxml.c" and "mxmldoc.c" source files
    for examples of using Mini-XML.

    Mini-XML provides a single header file which you include:

        #include <mxml.h>

    Nodes are defined by the "mxml_node_t" structure; the "type"
    member defines the node type (element, integer, opaque,
    real, or text) which determines which value you want to look
    at in the "value" union.  New nodes can be created using the
    "mxmlNewElement()", "mxmlNewInteger()", "mxmlNewOpaque()",
    "mxmlNewReal()", and "mxmlNewText()" functions.  Only
    elements can have child nodes, and the top node must be an
    element, usually "?xml".

    You load an XML file using the "mxmlLoadFile()" function:

        FILE *fp;
        mxml_node_t *tree;

	fp = fopen("filename.xml", "r");
	tree = mxmlLoadFile(NULL, fp, MXML_NO_CALLBACK);
	fclose(fp);

    Similarly, you save an XML file using the "mxmlSaveFile()"
    function:

        FILE *fp;
        mxml_node_t *tree;

	fp = fopen("filename.xml", "w");
	mxmlSaveFile(tree, fp, MXML_NO_CALLBACK);
	fclose(fp);

    The "mxmlLoadString()", "mxmlSaveAllocString()", and
    "mxmlSaveString()" functions load XML node trees from and
    save XML node trees to strings:

        char buffer[8192];
	char *ptr;
	mxml_node_t *tree;

        ...
	tree = mxmlLoadString(NULL, buffer, MXML_NO_CALLBACK);

        ...
        mxmlSaveString(tree, buffer, sizeof(buffer), MXML_NO_CALLBACK);

        ...
	ptr = mxmlSaveAllocString(tree, MXML_NO_CALLBACK);

    You can find a named element/node using the
    "mxmlFindElement()" function:

        mxml_node_t *node = mxmlFindElement(tree, tree, "name", "attr",
	                                    "value", MXML_DESCEND);

    The "name", "attr", and "value" arguments can be passed as
    NULL to act as wildcards, e.g.:

        /* Find the first "a" element */
        node = mxmlFindElement(tree, tree, "a", NULL, NULL, MXML_DESCEND);

        /* Find the first "a" element with "href" attribute */
        node = mxmlFindElement(tree, tree, "a", "href", NULL, MXML_DESCEND);

        /* Find the first "a" element with "href" to a URL */
        node = mxmlFindElement(tree, tree, "a", "href",
	                       "http://www.easysw.com/~mike/mxml/",
			       MXML_DESCEND);

        /* Find the first element with a "src" attribute*/
        node = mxmlFindElement(tree, tree, NULL, "src", NULL, MXML_DESCEND);

        /* Find the first element with a "src" = "foo.jpg" */
        node = mxmlFindElement(tree, tree, NULL, "src", "foo.jpg",
	                       MXML_DESCEND);

    You can also iterate with the same function:

        mxml_node_t *node;

	for (node = mxmlFindElement(tree, tree, "name", NULL, NULL,
	                            MXML_DESCEND);
	     node != NULL;
	     node = mxmlFindElement(node, tree, "name", NULL, NULL,
	                            MXML_DESCEND))
        {
	  ... do something ...
	}

    Finally, once you are done with the XML data, use the
    "mxmlDelete()" function to recursively free the memory that
    is used for a particular node or the entire tree:

        mxmlDelete(tree);


GETTING HELP AND REPORTING PROBLEMS

    The Mini-XML web site provides access to a discussion forum
    and bug reporting page:

        http://www.minixml.org/


LEGAL STUFF

    The Mini-XML library is Copyright 2003-2008 by Michael Sweet.

    This library is free software; you can redistribute it
    and/or modify it under the terms of the GNU Library General
    Public License as published by the Free Software Foundation;
    either version 2 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 Library General Public License for
    more details.

    You should have received a copy of the GNU Library General
    Public License along with this library; if not, write to the
    Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA
    02139, USA.