Commit | Line | Data |
---|---|---|
68270f0f | 1 | /* |
4b2b86f2 | 2 | * Copyright (C) 2014 EfficiOS Inc. |
68270f0f | 3 | * |
9d16b343 | 4 | * SPDX-License-Identifier: GPL-2.0-only |
68270f0f | 5 | * |
68270f0f JRJ |
6 | */ |
7 | ||
8 | /* | |
71f82f2b | 9 | * Usage: extract_xml [-v|-e] xml_path xpath_expression |
68270f0f JRJ |
10 | * Evaluate XPath expression and prints result node set. |
11 | * args[1] path to the xml file | |
12 | * args[2] xpath expression to extract | |
71f82f2b | 13 | * If -e look if node exist return "true" else nothing |
68270f0f JRJ |
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 | */ | |
83d6d6c4 | 27 | #include <stdbool.h> |
68270f0f | 28 | #include <stdio.h> |
83d6d6c4 | 29 | #include <stdlib.h> |
68270f0f | 30 | #include <string.h> |
68270f0f JRJ |
31 | #include <unistd.h> |
32 | ||
33 | #include <libxml/tree.h> | |
34 | #include <libxml/parser.h> | |
35 | #include <libxml/xpath.h> | |
36 | #include <libxml/xpathInternals.h> | |
41af1adf | 37 | #include <common/defaults.h> |
68270f0f JRJ |
38 | |
39 | #if defined(LIBXML_XPATH_ENABLED) | |
40 | ||
83d6d6c4 JR |
41 | static int opt_verbose; |
42 | static int node_exist; | |
43 | static bool result = false; | |
71f82f2b | 44 | |
68270f0f JRJ |
45 | /** |
46 | * print_xpath_nodes: | |
47 | * nodes: the nodes set. | |
48 | * output: the output file handle. | |
49 | * | |
50 | * Print the node content to the file | |
51 | */ | |
52 | static int print_xpath_nodes(xmlDocPtr doc, xmlNodeSetPtr nodes, FILE *output) | |
53 | { | |
71f82f2b | 54 | int ret = 0; |
68270f0f JRJ |
55 | int size; |
56 | int i; | |
57 | ||
58 | xmlNodePtr cur; | |
59 | xmlChar *node_child_value_string = NULL; | |
60 | ||
a0377dfe | 61 | LTTNG_ASSERT(output); |
68270f0f JRJ |
62 | size = (nodes) ? nodes->nodeNr : 0; |
63 | ||
64 | for (i = 0; i < size; ++i) { | |
a0377dfe | 65 | LTTNG_ASSERT(nodes->nodeTab[i]); |
68270f0f JRJ |
66 | |
67 | if (nodes->nodeTab[i]->type == XML_NAMESPACE_DECL) { | |
68 | fprintf(stderr, "ERR:%s\n", | |
69 | "This executable does not support xml namespacing\n"); | |
70 | ret = -1; | |
71 | goto end; | |
72 | } else if (nodes->nodeTab[i]->type == XML_ELEMENT_NODE) { | |
73 | cur = nodes->nodeTab[i]; | |
74 | ||
75 | if (xmlChildElementCount(cur) == 0) { | |
76 | if (xmlNodeIsText(cur->children)) { | |
77 | node_child_value_string = xmlNodeListGetString(doc, | |
78 | cur->children, 1); | |
71f82f2b | 79 | if (node_exist) { |
83d6d6c4 | 80 | result = true; |
71f82f2b | 81 | } else if (opt_verbose) { |
68270f0f JRJ |
82 | fprintf(output, "%s;%s;\n", cur->name, |
83 | node_child_value_string); | |
84 | } else { | |
85 | fprintf(output, "%s\n", | |
86 | node_child_value_string); | |
87 | } | |
88 | xmlFree(node_child_value_string); | |
71f82f2b JR |
89 | } else { |
90 | /* We don't want to print non-final element */ | |
91 | if (node_exist) { | |
83d6d6c4 | 92 | result = true; |
71f82f2b JR |
93 | } else { |
94 | fprintf(stderr, "ERR:%s\n", | |
95 | "Xpath expression return non-final xml element"); | |
96 | ret = -1; | |
97 | goto end; | |
98 | } | |
99 | } | |
100 | } else { | |
101 | if (node_exist) { | |
83d6d6c4 | 102 | result = true; |
68270f0f JRJ |
103 | } else { |
104 | /* We don't want to print non-final element */ | |
105 | fprintf(stderr, "ERR:%s\n", | |
106 | "Xpath expression return non-final xml element"); | |
107 | ret = -1; | |
108 | goto end; | |
109 | } | |
68270f0f JRJ |
110 | } |
111 | ||
112 | } else { | |
113 | cur = nodes->nodeTab[i]; | |
71f82f2b | 114 | if (node_exist) { |
83d6d6c4 | 115 | result = true; |
71f82f2b | 116 | } else if (opt_verbose) { |
68270f0f JRJ |
117 | fprintf(output, "%s;%s;\n", cur->parent->name, cur->content); |
118 | } else { | |
119 | fprintf(output, "%s\n", cur->content); | |
68270f0f JRJ |
120 | } |
121 | } | |
122 | } | |
123 | /* Command Success */ | |
124 | ret = 0; | |
125 | ||
126 | end: | |
127 | return ret; | |
128 | } | |
129 | ||
41af1adf JG |
130 | static int register_lttng_namespace(xmlXPathContextPtr xpathCtx) |
131 | { | |
132 | int ret; | |
133 | xmlChar *prefix; | |
134 | xmlChar *ns = NULL; | |
135 | ||
136 | prefix = xmlCharStrdup("lttng"); | |
137 | if (!prefix) { | |
138 | ret = -1; | |
139 | goto end; | |
140 | } | |
141 | ||
142 | ns = xmlCharStrdup(DEFAULT_LTTNG_MI_NAMESPACE); | |
143 | if (!ns) { | |
144 | ret = -1; | |
145 | goto end; | |
146 | } | |
147 | ||
148 | ret = xmlXPathRegisterNs(xpathCtx, prefix, ns); | |
41af1adf | 149 | end: |
0916f272 | 150 | xmlFree(prefix); |
41af1adf JG |
151 | xmlFree(ns); |
152 | return ret; | |
153 | } | |
154 | ||
68270f0f JRJ |
155 | /* |
156 | * Extract element corresponding to xpath | |
157 | * xml_path The path to the xml file | |
158 | * xpath: The xpath to evaluate. | |
159 | * | |
160 | * Evaluate an xpath expression onto an xml file. | |
161 | * and print the result one by line. | |
162 | * | |
163 | * Returns 0 on success and a negative value otherwise. | |
164 | */ | |
165 | static int extract_xpath(const char *xml_path, const xmlChar *xpath) | |
166 | { | |
41af1adf | 167 | int ret; |
68270f0f JRJ |
168 | xmlDocPtr doc = NULL; |
169 | xmlXPathContextPtr xpathCtx = NULL; | |
170 | xmlXPathObjectPtr xpathObj = NULL; | |
171 | ||
a0377dfe FD |
172 | LTTNG_ASSERT(xml_path); |
173 | LTTNG_ASSERT(xpath); | |
68270f0f JRJ |
174 | |
175 | /* Parse the xml file */ | |
176 | doc = xmlParseFile(xml_path); | |
177 | if (!doc) { | |
178 | fprintf(stderr, "ERR parsing: xml file invalid \"%s\"\n", xml_path); | |
179 | return -1; | |
180 | } | |
181 | ||
182 | /* Initialize a xpath context */ | |
183 | xpathCtx = xmlXPathNewContext(doc); | |
184 | if (!xpathCtx) { | |
185 | fprintf(stderr, "ERR: XPath context invalid\n"); | |
186 | xmlFreeDoc(doc); | |
187 | return -1; | |
188 | } | |
189 | ||
41af1adf JG |
190 | /* Register the LTTng MI namespace */ |
191 | ret = register_lttng_namespace(xpathCtx); | |
192 | if (ret) { | |
193 | fprintf(stderr, "ERR: Could not register lttng namespace\n"); | |
194 | xmlXPathFreeContext(xpathCtx); | |
195 | xmlFreeDoc(doc); | |
196 | return -1; | |
197 | } | |
198 | ||
68270f0f JRJ |
199 | /* Evaluate xpath expression */ |
200 | xpathObj = xmlXPathEvalExpression(xpath, xpathCtx); | |
201 | if (!xpathObj) { | |
202 | fprintf(stderr, "ERR: invalid xpath expression \"%s\"\n", xpath); | |
203 | xmlXPathFreeContext(xpathCtx); | |
204 | xmlFreeDoc(doc); | |
205 | return -1; | |
206 | } | |
207 | ||
208 | /* Print results */ | |
209 | if (print_xpath_nodes(doc, xpathObj->nodesetval, stdout)) { | |
210 | xmlXPathFreeObject(xpathObj); | |
211 | xmlXPathFreeContext(xpathCtx); | |
212 | xmlFreeDoc(doc); | |
213 | return -1; | |
214 | } | |
83d6d6c4 JR |
215 | if (node_exist && result) { |
216 | fprintf(stdout, "true\n"); | |
217 | } | |
68270f0f JRJ |
218 | |
219 | /* Cleanup */ | |
220 | xmlXPathFreeObject(xpathObj); | |
221 | xmlXPathFreeContext(xpathCtx); | |
222 | xmlFreeDoc(doc); | |
223 | ||
224 | return 0; | |
225 | } | |
226 | ||
227 | int main(int argc, char **argv) | |
228 | { | |
229 | int opt; | |
230 | ||
231 | /* Parse command line and process file */ | |
71f82f2b | 232 | while ((opt = getopt(argc, argv, "ve")) != -1) { |
68270f0f JRJ |
233 | switch (opt) { |
234 | case 'v': | |
235 | opt_verbose = 1; | |
236 | break; | |
71f82f2b JR |
237 | case 'e': |
238 | node_exist = 1; | |
239 | break; | |
68270f0f JRJ |
240 | default: |
241 | abort(); | |
242 | } | |
243 | } | |
244 | ||
245 | if (!(optind + 1 < argc)) { | |
246 | fprintf(stderr, "ERR:%s\n", "Arguments missing"); | |
247 | return -1; | |
248 | } | |
249 | ||
250 | /* Init libxml */ | |
251 | xmlInitParser(); | |
252 | xmlKeepBlanksDefault(0); | |
253 | if (access(argv[optind], F_OK)) { | |
254 | fprintf(stderr, "ERR:%s\n", "Xml path not valid"); | |
255 | return -1; | |
256 | } | |
257 | /* Do the main job */ | |
258 | if (extract_xpath(argv[optind], (xmlChar *)argv[optind+1])) { | |
259 | return -1; | |
260 | } | |
261 | ||
262 | /* Shutdown libxml */ | |
263 | xmlCleanupParser(); | |
264 | ||
265 | return 0; | |
266 | } | |
267 | ||
268 | #else | |
269 | int main(void) | |
270 | { | |
271 | fprintf(stderr, "XPath support not compiled in\n"); | |
272 | return -1; | |
273 | } | |
274 | #endif |