Introduce emission site for syscall event rule
[lttng-tools.git] / tests / regression / tools / mi / extract_xml.c
1 /*
2 * Copyright (C) 2014 Jonathan Rajotte <jonathan.r.julien@gmail.com>
3 *
4 * SPDX-License-Identifier: GPL-2.0-only
5 *
6 */
7
8 /*
9 * Usage: extract_xml [-v|-e] xml_path xpath_expression
10 * Evaluate XPath expression and prints result node set.
11 * args[1] path to the xml file
12 * args[2] xpath expression to extract
13 * If -e look if node exist return "true" else nothing
14 * If -v is set the name of the node will appear with his value delimited by
15 * a semicolon(;)
16 * Ex:
17 * Command:extract_xml ../file.xml /test/node/text()
18 * Output:
19 * a
20 * b
21 * c
22 * With -v
23 * node;a;
24 * node;b;
25 * node;c;
26 */
27 #include <assert.h>
28 #include <stdbool.h>
29 #include <stdio.h>
30 #include <stdlib.h>
31 #include <string.h>
32 #include <unistd.h>
33
34 #include <libxml/tree.h>
35 #include <libxml/parser.h>
36 #include <libxml/xpath.h>
37 #include <libxml/xpathInternals.h>
38 #include <common/defaults.h>
39
40 #if defined(LIBXML_XPATH_ENABLED)
41
42 static int opt_verbose;
43 static int node_exist;
44 static bool result = false;
45
46 /**
47 * print_xpath_nodes:
48 * nodes: the nodes set.
49 * output: the output file handle.
50 *
51 * Print the node content to the file
52 */
53 static int print_xpath_nodes(xmlDocPtr doc, xmlNodeSetPtr nodes, FILE *output)
54 {
55 int ret = 0;
56 int size;
57 int i;
58
59 xmlNodePtr cur;
60 xmlChar *node_child_value_string = NULL;
61
62 assert(output);
63 size = (nodes) ? nodes->nodeNr : 0;
64
65 for (i = 0; i < size; ++i) {
66 assert(nodes->nodeTab[i]);
67
68 if (nodes->nodeTab[i]->type == XML_NAMESPACE_DECL) {
69 fprintf(stderr, "ERR:%s\n",
70 "This executable does not support xml namespacing\n");
71 ret = -1;
72 goto end;
73 } else if (nodes->nodeTab[i]->type == XML_ELEMENT_NODE) {
74 cur = nodes->nodeTab[i];
75
76 if (xmlChildElementCount(cur) == 0) {
77 if (xmlNodeIsText(cur->children)) {
78 node_child_value_string = xmlNodeListGetString(doc,
79 cur->children, 1);
80 if (node_exist) {
81 result = true;
82 } else if (opt_verbose) {
83 fprintf(output, "%s;%s;\n", cur->name,
84 node_child_value_string);
85 } else {
86 fprintf(output, "%s\n",
87 node_child_value_string);
88 }
89 xmlFree(node_child_value_string);
90 } else {
91 /* We don't want to print non-final element */
92 if (node_exist) {
93 result = true;
94 } else {
95 fprintf(stderr, "ERR:%s\n",
96 "Xpath expression return non-final xml element");
97 ret = -1;
98 goto end;
99 }
100 }
101 } else {
102 if (node_exist) {
103 result = true;
104 } else {
105 /* We don't want to print non-final element */
106 fprintf(stderr, "ERR:%s\n",
107 "Xpath expression return non-final xml element");
108 ret = -1;
109 goto end;
110 }
111 }
112
113 } else {
114 cur = nodes->nodeTab[i];
115 if (node_exist) {
116 result = true;
117 } else if (opt_verbose) {
118 fprintf(output, "%s;%s;\n", cur->parent->name, cur->content);
119 } else {
120 fprintf(output, "%s\n", cur->content);
121 }
122 }
123 }
124 /* Command Success */
125 ret = 0;
126
127 end:
128 return ret;
129 }
130
131 static int register_lttng_namespace(xmlXPathContextPtr xpathCtx)
132 {
133 int ret;
134 xmlChar *prefix;
135 xmlChar *ns = NULL;
136
137 prefix = xmlCharStrdup("lttng");
138 if (!prefix) {
139 ret = -1;
140 goto end;
141 }
142
143 ns = xmlCharStrdup(DEFAULT_LTTNG_MI_NAMESPACE);
144 if (!ns) {
145 ret = -1;
146 goto end;
147 }
148
149 ret = xmlXPathRegisterNs(xpathCtx, prefix, ns);
150 end:
151 xmlFree(prefix);
152 xmlFree(ns);
153 return ret;
154 }
155
156 /*
157 * Extract element corresponding to xpath
158 * xml_path The path to the xml file
159 * xpath: The xpath to evaluate.
160 *
161 * Evaluate an xpath expression onto an xml file.
162 * and print the result one by line.
163 *
164 * Returns 0 on success and a negative value otherwise.
165 */
166 static int extract_xpath(const char *xml_path, const xmlChar *xpath)
167 {
168 int ret;
169 xmlDocPtr doc = NULL;
170 xmlXPathContextPtr xpathCtx = NULL;
171 xmlXPathObjectPtr xpathObj = NULL;
172
173 assert(xml_path);
174 assert(xpath);
175
176 /* Parse the xml file */
177 doc = xmlParseFile(xml_path);
178 if (!doc) {
179 fprintf(stderr, "ERR parsing: xml file invalid \"%s\"\n", xml_path);
180 return -1;
181 }
182
183 /* Initialize a xpath context */
184 xpathCtx = xmlXPathNewContext(doc);
185 if (!xpathCtx) {
186 fprintf(stderr, "ERR: XPath context invalid\n");
187 xmlFreeDoc(doc);
188 return -1;
189 }
190
191 /* Register the LTTng MI namespace */
192 ret = register_lttng_namespace(xpathCtx);
193 if (ret) {
194 fprintf(stderr, "ERR: Could not register lttng namespace\n");
195 xmlXPathFreeContext(xpathCtx);
196 xmlFreeDoc(doc);
197 return -1;
198 }
199
200 /* Evaluate xpath expression */
201 xpathObj = xmlXPathEvalExpression(xpath, xpathCtx);
202 if (!xpathObj) {
203 fprintf(stderr, "ERR: invalid xpath expression \"%s\"\n", xpath);
204 xmlXPathFreeContext(xpathCtx);
205 xmlFreeDoc(doc);
206 return -1;
207 }
208
209 /* Print results */
210 if (print_xpath_nodes(doc, xpathObj->nodesetval, stdout)) {
211 xmlXPathFreeObject(xpathObj);
212 xmlXPathFreeContext(xpathCtx);
213 xmlFreeDoc(doc);
214 return -1;
215 }
216 if (node_exist && result) {
217 fprintf(stdout, "true\n");
218 }
219
220 /* Cleanup */
221 xmlXPathFreeObject(xpathObj);
222 xmlXPathFreeContext(xpathCtx);
223 xmlFreeDoc(doc);
224
225 return 0;
226 }
227
228 int main(int argc, char **argv)
229 {
230 int opt;
231
232 /* Parse command line and process file */
233 while ((opt = getopt(argc, argv, "ve")) != -1) {
234 switch (opt) {
235 case 'v':
236 opt_verbose = 1;
237 break;
238 case 'e':
239 node_exist = 1;
240 break;
241 default:
242 abort();
243 }
244 }
245
246 if (!(optind + 1 < argc)) {
247 fprintf(stderr, "ERR:%s\n", "Arguments missing");
248 return -1;
249 }
250
251 /* Init libxml */
252 xmlInitParser();
253 xmlKeepBlanksDefault(0);
254 if (access(argv[optind], F_OK)) {
255 fprintf(stderr, "ERR:%s\n", "Xml path not valid");
256 return -1;
257 }
258 /* Do the main job */
259 if (extract_xpath(argv[optind], (xmlChar *)argv[optind+1])) {
260 return -1;
261 }
262
263 /* Shutdown libxml */
264 xmlCleanupParser();
265
266 return 0;
267 }
268
269 #else
270 int main(void)
271 {
272 fprintf(stderr, "XPath support not compiled in\n");
273 return -1;
274 }
275 #endif
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