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68270f0f JRJ |
1 | /* |
2 | * Copyright (C) 2014 - Jonathan Rajotte <jonathan.r.julien@gmail.com> | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify it | |
5 | * under the terms of the GNU General Public License, version 2 only, as | |
6 | * published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope that it will be useful, but WITHOUT | |
9 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
10 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
11 | * more details. | |
12 | * | |
13 | * You should have received a copy of the GNU General Public License along with | |
14 | * this program; if not, write to the Free Software Foundation, Inc., 51 | |
15 | */ | |
16 | ||
17 | /* | |
71f82f2b | 18 | * Usage: extract_xml [-v|-e] xml_path xpath_expression |
68270f0f JRJ |
19 | * Evaluate XPath expression and prints result node set. |
20 | * args[1] path to the xml file | |
21 | * args[2] xpath expression to extract | |
71f82f2b | 22 | * If -e look if node exist return "true" else nothing |
68270f0f JRJ |
23 | * If -v is set the name of the node will appear with his value delimited by |
24 | * a semicolon(;) | |
25 | * Ex: | |
26 | * Command:extract_xml ../file.xml /test/node/text() | |
27 | * Output: | |
28 | * a | |
29 | * b | |
30 | * c | |
31 | * With -v | |
32 | * node;a; | |
33 | * node;b; | |
34 | * node;c; | |
35 | */ | |
36 | #include <stdlib.h> | |
37 | #include <stdio.h> | |
38 | #include <string.h> | |
39 | #include <assert.h> | |
40 | #include <unistd.h> | |
41 | ||
42 | #include <libxml/tree.h> | |
43 | #include <libxml/parser.h> | |
44 | #include <libxml/xpath.h> | |
45 | #include <libxml/xpathInternals.h> | |
41af1adf | 46 | #include <common/defaults.h> |
68270f0f JRJ |
47 | |
48 | #if defined(LIBXML_XPATH_ENABLED) | |
49 | ||
50 | ||
51 | int opt_verbose; | |
71f82f2b JR |
52 | int node_exist; |
53 | ||
68270f0f JRJ |
54 | /** |
55 | * print_xpath_nodes: | |
56 | * nodes: the nodes set. | |
57 | * output: the output file handle. | |
58 | * | |
59 | * Print the node content to the file | |
60 | */ | |
61 | static int print_xpath_nodes(xmlDocPtr doc, xmlNodeSetPtr nodes, FILE *output) | |
62 | { | |
71f82f2b | 63 | int ret = 0; |
68270f0f JRJ |
64 | int size; |
65 | int i; | |
66 | ||
67 | xmlNodePtr cur; | |
68 | xmlChar *node_child_value_string = NULL; | |
69 | ||
70 | assert(output); | |
71 | size = (nodes) ? nodes->nodeNr : 0; | |
72 | ||
73 | for (i = 0; i < size; ++i) { | |
74 | assert(nodes->nodeTab[i]); | |
75 | ||
76 | if (nodes->nodeTab[i]->type == XML_NAMESPACE_DECL) { | |
77 | fprintf(stderr, "ERR:%s\n", | |
78 | "This executable does not support xml namespacing\n"); | |
79 | ret = -1; | |
80 | goto end; | |
81 | } else if (nodes->nodeTab[i]->type == XML_ELEMENT_NODE) { | |
82 | cur = nodes->nodeTab[i]; | |
83 | ||
84 | if (xmlChildElementCount(cur) == 0) { | |
85 | if (xmlNodeIsText(cur->children)) { | |
86 | node_child_value_string = xmlNodeListGetString(doc, | |
87 | cur->children, 1); | |
71f82f2b JR |
88 | if (node_exist) { |
89 | fprintf(output, "true\n"); | |
90 | } else if (opt_verbose) { | |
68270f0f JRJ |
91 | fprintf(output, "%s;%s;\n", cur->name, |
92 | node_child_value_string); | |
93 | } else { | |
94 | fprintf(output, "%s\n", | |
95 | node_child_value_string); | |
96 | } | |
97 | xmlFree(node_child_value_string); | |
71f82f2b JR |
98 | } else { |
99 | /* We don't want to print non-final element */ | |
100 | if (node_exist) { | |
101 | fprintf(output, "true\n"); | |
102 | } else { | |
103 | fprintf(stderr, "ERR:%s\n", | |
104 | "Xpath expression return non-final xml element"); | |
105 | ret = -1; | |
106 | goto end; | |
107 | } | |
108 | } | |
109 | } else { | |
110 | if (node_exist) { | |
111 | fprintf(output, "true\n"); | |
68270f0f JRJ |
112 | } else { |
113 | /* We don't want to print non-final element */ | |
114 | fprintf(stderr, "ERR:%s\n", | |
115 | "Xpath expression return non-final xml element"); | |
116 | ret = -1; | |
117 | goto end; | |
118 | } | |
68270f0f JRJ |
119 | } |
120 | ||
121 | } else { | |
122 | cur = nodes->nodeTab[i]; | |
71f82f2b JR |
123 | if (node_exist) { |
124 | fprintf(output, "true\n"); | |
125 | } else if (opt_verbose) { | |
68270f0f JRJ |
126 | fprintf(output, "%s;%s;\n", cur->parent->name, cur->content); |
127 | } else { | |
128 | fprintf(output, "%s\n", cur->content); | |
68270f0f JRJ |
129 | } |
130 | } | |
131 | } | |
132 | /* Command Success */ | |
133 | ret = 0; | |
134 | ||
135 | end: | |
136 | return ret; | |
137 | } | |
138 | ||
41af1adf JG |
139 | static int register_lttng_namespace(xmlXPathContextPtr xpathCtx) |
140 | { | |
141 | int ret; | |
142 | xmlChar *prefix; | |
143 | xmlChar *ns = NULL; | |
144 | ||
145 | prefix = xmlCharStrdup("lttng"); | |
146 | if (!prefix) { | |
147 | ret = -1; | |
148 | goto end; | |
149 | } | |
150 | ||
151 | ns = xmlCharStrdup(DEFAULT_LTTNG_MI_NAMESPACE); | |
152 | if (!ns) { | |
153 | ret = -1; | |
154 | goto end; | |
155 | } | |
156 | ||
157 | ret = xmlXPathRegisterNs(xpathCtx, prefix, ns); | |
41af1adf | 158 | end: |
0916f272 | 159 | xmlFree(prefix); |
41af1adf JG |
160 | xmlFree(ns); |
161 | return ret; | |
162 | } | |
163 | ||
68270f0f JRJ |
164 | /* |
165 | * Extract element corresponding to xpath | |
166 | * xml_path The path to the xml file | |
167 | * xpath: The xpath to evaluate. | |
168 | * | |
169 | * Evaluate an xpath expression onto an xml file. | |
170 | * and print the result one by line. | |
171 | * | |
172 | * Returns 0 on success and a negative value otherwise. | |
173 | */ | |
174 | static int extract_xpath(const char *xml_path, const xmlChar *xpath) | |
175 | { | |
41af1adf | 176 | int ret; |
68270f0f JRJ |
177 | xmlDocPtr doc = NULL; |
178 | xmlXPathContextPtr xpathCtx = NULL; | |
179 | xmlXPathObjectPtr xpathObj = NULL; | |
180 | ||
181 | assert(xml_path); | |
182 | assert(xpath); | |
183 | ||
184 | /* Parse the xml file */ | |
185 | doc = xmlParseFile(xml_path); | |
186 | if (!doc) { | |
187 | fprintf(stderr, "ERR parsing: xml file invalid \"%s\"\n", xml_path); | |
188 | return -1; | |
189 | } | |
190 | ||
191 | /* Initialize a xpath context */ | |
192 | xpathCtx = xmlXPathNewContext(doc); | |
193 | if (!xpathCtx) { | |
194 | fprintf(stderr, "ERR: XPath context invalid\n"); | |
195 | xmlFreeDoc(doc); | |
196 | return -1; | |
197 | } | |
198 | ||
41af1adf JG |
199 | /* Register the LTTng MI namespace */ |
200 | ret = register_lttng_namespace(xpathCtx); | |
201 | if (ret) { | |
202 | fprintf(stderr, "ERR: Could not register lttng namespace\n"); | |
203 | xmlXPathFreeContext(xpathCtx); | |
204 | xmlFreeDoc(doc); | |
205 | return -1; | |
206 | } | |
207 | ||
68270f0f JRJ |
208 | /* Evaluate xpath expression */ |
209 | xpathObj = xmlXPathEvalExpression(xpath, xpathCtx); | |
210 | if (!xpathObj) { | |
211 | fprintf(stderr, "ERR: invalid xpath expression \"%s\"\n", xpath); | |
212 | xmlXPathFreeContext(xpathCtx); | |
213 | xmlFreeDoc(doc); | |
214 | return -1; | |
215 | } | |
216 | ||
217 | /* Print results */ | |
218 | if (print_xpath_nodes(doc, xpathObj->nodesetval, stdout)) { | |
219 | xmlXPathFreeObject(xpathObj); | |
220 | xmlXPathFreeContext(xpathCtx); | |
221 | xmlFreeDoc(doc); | |
222 | return -1; | |
223 | } | |
224 | ||
225 | /* Cleanup */ | |
226 | xmlXPathFreeObject(xpathObj); | |
227 | xmlXPathFreeContext(xpathCtx); | |
228 | xmlFreeDoc(doc); | |
229 | ||
230 | return 0; | |
231 | } | |
232 | ||
233 | int main(int argc, char **argv) | |
234 | { | |
235 | int opt; | |
236 | ||
237 | /* Parse command line and process file */ | |
71f82f2b | 238 | while ((opt = getopt(argc, argv, "ve")) != -1) { |
68270f0f JRJ |
239 | switch (opt) { |
240 | case 'v': | |
241 | opt_verbose = 1; | |
242 | break; | |
71f82f2b JR |
243 | case 'e': |
244 | node_exist = 1; | |
245 | break; | |
68270f0f JRJ |
246 | default: |
247 | abort(); | |
248 | } | |
249 | } | |
250 | ||
251 | if (!(optind + 1 < argc)) { | |
252 | fprintf(stderr, "ERR:%s\n", "Arguments missing"); | |
253 | return -1; | |
254 | } | |
255 | ||
256 | /* Init libxml */ | |
257 | xmlInitParser(); | |
258 | xmlKeepBlanksDefault(0); | |
259 | if (access(argv[optind], F_OK)) { | |
260 | fprintf(stderr, "ERR:%s\n", "Xml path not valid"); | |
261 | return -1; | |
262 | } | |
263 | /* Do the main job */ | |
264 | if (extract_xpath(argv[optind], (xmlChar *)argv[optind+1])) { | |
265 | return -1; | |
266 | } | |
267 | ||
268 | /* Shutdown libxml */ | |
269 | xmlCleanupParser(); | |
270 | ||
271 | return 0; | |
272 | } | |
273 | ||
274 | #else | |
275 | int main(void) | |
276 | { | |
277 | fprintf(stderr, "XPath support not compiled in\n"); | |
278 | return -1; | |
279 | } | |
280 | #endif |