Mini-XML Home Page

Current Release: v1.1.1, July 22, 2003
[ Download Source (.tar.gz 70k) | Download Linux RPM (.i386.rpm 64k) | Change Log | Documentation | Rate/Make Comments ]

Introduction

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 and writing of UTF-8 encoded XML files.
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, nor does it support character entities other than those required by the XML specification. Also, since Mini-XML does not support the UTF-16 encoding, it is technically not a conforming XML consumer/client.

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

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

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 currently a work in progress. Aside from the information that follows, the documentation page provides a handy reference and is automatically generated using Mini-XML. 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

You can email me at "mxml at easysw dot com" to report problems and/or ask for help. Just don't expect an instant response, as I get a lot of email...

Legal Stuff

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.