Commit | Line | Data |
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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 | */ | |
051356a8 SM |
27 | #include "common.hpp" |
28 | ||
28ab034a JG |
29 | #include <common/defaults.hpp> |
30 | ||
31 | #include <libxml/parser.h> | |
32 | #include <libxml/tree.h> | |
33 | #include <libxml/xpath.h> | |
34 | #include <libxml/xpathInternals.h> | |
83d6d6c4 | 35 | #include <stdbool.h> |
68270f0f | 36 | #include <stdio.h> |
83d6d6c4 | 37 | #include <stdlib.h> |
68270f0f | 38 | #include <string.h> |
68270f0f JRJ |
39 | #include <unistd.h> |
40 | ||
f59edc7c JG |
41 | namespace ll = lttng::libxml; |
42 | ||
68270f0f JRJ |
43 | #if defined(LIBXML_XPATH_ENABLED) |
44 | ||
83d6d6c4 JR |
45 | static int opt_verbose; |
46 | static int node_exist; | |
47 | static bool result = false; | |
71f82f2b | 48 | |
68270f0f JRJ |
49 | /** |
50 | * print_xpath_nodes: | |
51 | * nodes: the nodes set. | |
52 | * output: the output file handle. | |
53 | * | |
54 | * Print the node content to the file | |
55 | */ | |
56 | static int print_xpath_nodes(xmlDocPtr doc, xmlNodeSetPtr nodes, FILE *output) | |
57 | { | |
71f82f2b | 58 | int ret = 0; |
68270f0f JRJ |
59 | int size; |
60 | int i; | |
61 | ||
62 | xmlNodePtr cur; | |
cd9adb8b | 63 | xmlChar *node_child_value_string = nullptr; |
68270f0f | 64 | |
a0377dfe | 65 | LTTNG_ASSERT(output); |
68270f0f JRJ |
66 | size = (nodes) ? nodes->nodeNr : 0; |
67 | ||
68 | for (i = 0; i < size; ++i) { | |
a0377dfe | 69 | LTTNG_ASSERT(nodes->nodeTab[i]); |
68270f0f JRJ |
70 | |
71 | if (nodes->nodeTab[i]->type == XML_NAMESPACE_DECL) { | |
28ab034a JG |
72 | fprintf(stderr, |
73 | "ERR:%s\n", | |
74 | "This executable does not support xml namespacing\n"); | |
68270f0f JRJ |
75 | ret = -1; |
76 | goto end; | |
77 | } else if (nodes->nodeTab[i]->type == XML_ELEMENT_NODE) { | |
78 | cur = nodes->nodeTab[i]; | |
79 | ||
80 | if (xmlChildElementCount(cur) == 0) { | |
81 | if (xmlNodeIsText(cur->children)) { | |
28ab034a JG |
82 | node_child_value_string = |
83 | xmlNodeListGetString(doc, cur->children, 1); | |
71f82f2b | 84 | if (node_exist) { |
83d6d6c4 | 85 | result = true; |
71f82f2b | 86 | } else if (opt_verbose) { |
28ab034a JG |
87 | fprintf(output, |
88 | "%s;%s;\n", | |
89 | cur->name, | |
90 | node_child_value_string); | |
68270f0f | 91 | } else { |
28ab034a | 92 | fprintf(output, "%s\n", node_child_value_string); |
68270f0f JRJ |
93 | } |
94 | xmlFree(node_child_value_string); | |
71f82f2b JR |
95 | } else { |
96 | /* We don't want to print non-final element */ | |
97 | if (node_exist) { | |
83d6d6c4 | 98 | result = true; |
71f82f2b | 99 | } else { |
28ab034a JG |
100 | fprintf(stderr, |
101 | "ERR:%s\n", | |
102 | "Xpath expression return non-final xml element"); | |
71f82f2b JR |
103 | ret = -1; |
104 | goto end; | |
105 | } | |
106 | } | |
107 | } else { | |
108 | if (node_exist) { | |
83d6d6c4 | 109 | result = true; |
68270f0f JRJ |
110 | } else { |
111 | /* We don't want to print non-final element */ | |
28ab034a JG |
112 | fprintf(stderr, |
113 | "ERR:%s\n", | |
114 | "Xpath expression return non-final xml element"); | |
68270f0f JRJ |
115 | ret = -1; |
116 | goto end; | |
117 | } | |
68270f0f JRJ |
118 | } |
119 | ||
120 | } else { | |
121 | cur = nodes->nodeTab[i]; | |
71f82f2b | 122 | if (node_exist) { |
83d6d6c4 | 123 | result = true; |
71f82f2b | 124 | } else if (opt_verbose) { |
68270f0f JRJ |
125 | fprintf(output, "%s;%s;\n", cur->parent->name, cur->content); |
126 | } else { | |
127 | fprintf(output, "%s\n", cur->content); | |
68270f0f JRJ |
128 | } |
129 | } | |
130 | } | |
131 | /* Command Success */ | |
132 | ret = 0; | |
133 | ||
134 | end: | |
135 | return ret; | |
136 | } | |
137 | ||
41af1adf JG |
138 | static int register_lttng_namespace(xmlXPathContextPtr xpathCtx) |
139 | { | |
140 | int ret; | |
141 | xmlChar *prefix; | |
cd9adb8b | 142 | xmlChar *ns = nullptr; |
41af1adf JG |
143 | |
144 | prefix = xmlCharStrdup("lttng"); | |
145 | if (!prefix) { | |
146 | ret = -1; | |
147 | goto end; | |
148 | } | |
149 | ||
150 | ns = xmlCharStrdup(DEFAULT_LTTNG_MI_NAMESPACE); | |
151 | if (!ns) { | |
152 | ret = -1; | |
153 | goto end; | |
154 | } | |
155 | ||
156 | ret = xmlXPathRegisterNs(xpathCtx, prefix, ns); | |
41af1adf | 157 | end: |
0916f272 | 158 | xmlFree(prefix); |
41af1adf JG |
159 | xmlFree(ns); |
160 | return ret; | |
161 | } | |
162 | ||
68270f0f JRJ |
163 | /* |
164 | * Extract element corresponding to xpath | |
165 | * xml_path The path to the xml file | |
166 | * xpath: The xpath to evaluate. | |
167 | * | |
168 | * Evaluate an xpath expression onto an xml file. | |
169 | * and print the result one by line. | |
170 | * | |
171 | * Returns 0 on success and a negative value otherwise. | |
172 | */ | |
173 | static int extract_xpath(const char *xml_path, const xmlChar *xpath) | |
174 | { | |
41af1adf | 175 | int ret; |
cd9adb8b JG |
176 | xmlDocPtr doc = nullptr; |
177 | xmlXPathContextPtr xpathCtx = nullptr; | |
178 | xmlXPathObjectPtr xpathObj = nullptr; | |
68270f0f | 179 | |
a0377dfe FD |
180 | LTTNG_ASSERT(xml_path); |
181 | LTTNG_ASSERT(xpath); | |
68270f0f | 182 | |
f59edc7c | 183 | ll::parser_ctx_uptr parserCtx{ xmlNewParserCtxt() }; |
051356a8 SM |
184 | |
185 | if (!parserCtx) { | |
186 | fprintf(stderr, "ERR: could not allocate an XML parser context\n"); | |
187 | return -1; | |
188 | } | |
189 | ||
68270f0f | 190 | /* Parse the xml file */ |
051356a8 | 191 | doc = xmlCtxtReadFile(parserCtx.get(), xml_path, nullptr, XML_PARSE_NOBLANKS); |
68270f0f JRJ |
192 | if (!doc) { |
193 | fprintf(stderr, "ERR parsing: xml file invalid \"%s\"\n", xml_path); | |
194 | return -1; | |
195 | } | |
196 | ||
197 | /* Initialize a xpath context */ | |
198 | xpathCtx = xmlXPathNewContext(doc); | |
199 | if (!xpathCtx) { | |
200 | fprintf(stderr, "ERR: XPath context invalid\n"); | |
201 | xmlFreeDoc(doc); | |
202 | return -1; | |
203 | } | |
204 | ||
41af1adf JG |
205 | /* Register the LTTng MI namespace */ |
206 | ret = register_lttng_namespace(xpathCtx); | |
207 | if (ret) { | |
208 | fprintf(stderr, "ERR: Could not register lttng namespace\n"); | |
209 | xmlXPathFreeContext(xpathCtx); | |
210 | xmlFreeDoc(doc); | |
211 | return -1; | |
212 | } | |
213 | ||
68270f0f JRJ |
214 | /* Evaluate xpath expression */ |
215 | xpathObj = xmlXPathEvalExpression(xpath, xpathCtx); | |
216 | if (!xpathObj) { | |
217 | fprintf(stderr, "ERR: invalid xpath expression \"%s\"\n", xpath); | |
218 | xmlXPathFreeContext(xpathCtx); | |
219 | xmlFreeDoc(doc); | |
220 | return -1; | |
221 | } | |
222 | ||
223 | /* Print results */ | |
224 | if (print_xpath_nodes(doc, xpathObj->nodesetval, stdout)) { | |
225 | xmlXPathFreeObject(xpathObj); | |
226 | xmlXPathFreeContext(xpathCtx); | |
227 | xmlFreeDoc(doc); | |
228 | return -1; | |
229 | } | |
83d6d6c4 JR |
230 | if (node_exist && result) { |
231 | fprintf(stdout, "true\n"); | |
232 | } | |
68270f0f JRJ |
233 | |
234 | /* Cleanup */ | |
235 | xmlXPathFreeObject(xpathObj); | |
236 | xmlXPathFreeContext(xpathCtx); | |
237 | xmlFreeDoc(doc); | |
238 | ||
239 | return 0; | |
240 | } | |
241 | ||
242 | int main(int argc, char **argv) | |
243 | { | |
244 | int opt; | |
245 | ||
246 | /* Parse command line and process file */ | |
71f82f2b | 247 | while ((opt = getopt(argc, argv, "ve")) != -1) { |
68270f0f JRJ |
248 | switch (opt) { |
249 | case 'v': | |
250 | opt_verbose = 1; | |
251 | break; | |
71f82f2b JR |
252 | case 'e': |
253 | node_exist = 1; | |
254 | break; | |
68270f0f JRJ |
255 | default: |
256 | abort(); | |
257 | } | |
258 | } | |
259 | ||
260 | if (!(optind + 1 < argc)) { | |
261 | fprintf(stderr, "ERR:%s\n", "Arguments missing"); | |
262 | return -1; | |
263 | } | |
264 | ||
265 | /* Init libxml */ | |
266 | xmlInitParser(); | |
68270f0f JRJ |
267 | if (access(argv[optind], F_OK)) { |
268 | fprintf(stderr, "ERR:%s\n", "Xml path not valid"); | |
269 | return -1; | |
270 | } | |
271 | /* Do the main job */ | |
28ab034a | 272 | if (extract_xpath(argv[optind], (xmlChar *) argv[optind + 1])) { |
68270f0f JRJ |
273 | return -1; |
274 | } | |
275 | ||
276 | /* Shutdown libxml */ | |
277 | xmlCleanupParser(); | |
278 | ||
279 | return 0; | |
280 | } | |
281 | ||
282 | #else | |
283 | int main(void) | |
284 | { | |
285 | fprintf(stderr, "XPath support not compiled in\n"); | |
286 | return -1; | |
287 | } | |
288 | #endif |