1 This library is specially designed for reading xml configuration files and
2 to be as low on memory management as possible. Modifying or writing xml files
3 is not planned for the future. In most situations being able to gather data
4 by reading an xml file is more than enough and the read-only decision
5 provides a number of advantages over a one-size fits all approach. For isntance
6 the memory footprint can be kept low and the library can be kept simple.
8 To achieve these goals the mmap function is used to map the configuration file
9 to a memory region. The only places where memory is allocated is when creating
10 a new XML-id, when requesting a string from a node, when requestiong the node
11 name or when a request is made to copy a node into a new memory region.
13 Using this library should be pretty simple for most tasks; just open a file,
14 read every parameter one by one and close the id again.
18 xid = xmlOpen("/tmp/file.xml");
19 xpos = xmlNodeGetDouble(xid, "/configuration/x-pos");
20 ypos = xmlNodeGetDouble(xid, "/configuration/y-pos");
21 zpos = xmlNodeGetDouble(xid, "/configuration/z-pos");
25 While it is certainly possible to access every node directly by calling the
26 xmlNodeGet(Int/Double/String) functions, when more than one node need to be
27 gathered from a parent node it is advised to get the id of the parent node
28 and work from there since the XML-id holds the boundaries of the (parent)node
29 which limits the searching area resulting in improved searching speed.
34 xnid = xmlNodeGet(id, "/configuration/setup/");
35 version = xmlNodeGetDouble(xnid, "version");
36 s = xmlNodeGetString(xnid, "author");
42 Overview of the available functions:
43 -----------------------------------------------------------------------------
45 # Functions to Open and Close the XML file
47 # id = xmlOpen("/tmp/file.xml");
50 void *xmlOpen(const char *filename);
51 void *xmlInitBuffer(const char *buffer, size_t size);
52 void xmlClose(void *xid);
55 # Get the Id of a node at the specified path
57 # xnid = xmlNodeGet(id, "/path/to/specified/node");
59 void *xmlNodeGet(const void *xid, const char *path);
60 void *xmlNodeCopy(const void *xid, const char *path);
63 # Functions to walk the node tree and process them one by one.
65 # xmid = xmlMarkId(id);
66 # num = xmlNodeGetNum(xmid, "node");
67 # for (i=0; i<num; i++) {
68 # if (xmlNodeGetPos(id, xmid, "element", i) != 0) {
69 # if ((s = xmlGetString(xmid)) != 0) {
77 void *xmlMarkId(const void *xid);
78 unsigned int xmlNodeGetNum(const void *xid, const char *path);
79 void *xmlNodeGetPos(const void *pid, void *xid, const char *element, int pos);
82 # Get the name of the current node
84 char *xmlNodeGetName(const void *xid);
85 size_t xmlNodeCopyName(const void *xid, const char *buffer, size_t size);
88 # These functions work on the current node.
90 # xnid = xmlNodeGet(id, "/path/to/last/node");
91 # i = xmlGetInt(xnid);
93 # xnid = xmlNodeGet(id, "/path/to/specified/node");
94 # if (xmlCompareString(xnid, "value") == 0) printf("We have a match!\n");
96 long int xmlGetInt(const void *xid);
97 double xmlGetDouble(const void *xid);
98 char *xmlGetString(const void *xid);
99 size_t xmlCopyString(const void *xid, char *buffer, const size_t size);
100 int xmlCompareString(const void *xid, const char *str);
103 # These functions work on a specified node path
105 # d = xmlNodeGetDouble(id, "/path/to/node");
107 # xnid = xmlNodeGet(id, "/path/to");
108 # i = xmlNodeGetInt(xnid, "node");
110 long int xmlNodeGetInt(const void *xid, const char *path);
111 double xmlNodeGetDouble(const void *xid, const char *path);
112 char *xmlNodeGetString(const void *xid, const char *path);
113 size_t xmlNodeCopyString(const void *xid, const char *path,
114 char *buffer, const size_t size);
115 int xmlNodeCompareString(const void *xid, const char *path, const char *str);
118 # These functions work on a specified atribute
120 # i = xmlAttributeGetInt(id, "n");
123 # s = xmlAttributeGetString(id, "type");
124 # if (s) printf("node is of type '%s'\n", s);
127 long int xmlAttributeGetInt(const void *xid, const char *attr);
128 double xmlAttributeGetDouble(const void *xid, const char *attr);
129 char *xmlAttributeGetString(const void *xid, const char *attr);
130 size_t xmlAttributeCopyString(const void *xid, const char *attr,
131 const char *buffer, size_t size);
132 int xmlAttributeCompareString(const void *xid, const char *attr,
136 # Error detection and reporting functions
138 # char *err_str = xmlErrorGetString(id, 0);
139 # size_t err_lineno = xmlErrorGetLineNo(id, 0);
140 # int err = xmlErrorGetNo(id, 1); /* clear last error */
141 # if (err) printf("Error #%i at line %u: '%s'\n", err, err_lineno, err_str);
143 int xmlErrorGetNo(const void *xid, int clear);
144 size_t xmlErrorGetLineNo(const void *xid, int clear);
145 size_t xmlErrorGetColumnNo(const void *xid, int clear);
146 const char *xmlErrorGetString(const void *xid, int clear);