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f640bcb3 RK |
1 | /* |
2 | * This file is part of DisOrder | |
3 | * Copyright (C) 2008 Richard Kettlewell | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or modify | |
6 | * it under the terms of the GNU General Public License as published by | |
7 | * the Free Software Foundation; either version 2 of the License, or | |
8 | * (at your option) any later version. | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, but | |
11 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
13 | * General Public License for more details. | |
14 | * | |
15 | * You should have received a copy of the GNU General Public License | |
16 | * along with this program; if not, write to the Free Software | |
17 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 | |
18 | * USA | |
19 | */ | |
20 | ||
21 | /** @file lib/macros-builtin.c | |
22 | * @brief Built-in expansions | |
23 | * | |
b36be3a1 RK |
24 | * This is a grab-bag of non-domain-specific expansions. Documentation will be |
25 | * generated from the comments at the head of each function. | |
f640bcb3 RK |
26 | */ |
27 | ||
28 | #include <config.h> | |
29 | #include "types.h" | |
30 | ||
31 | #include <stdio.h> | |
32 | #include <string.h> | |
33 | #include <errno.h> | |
34 | #include <assert.h> | |
35 | #include <unistd.h> | |
b36be3a1 RK |
36 | #include <fcntl.h> |
37 | #include <sys/stat.h> | |
f640bcb3 | 38 | |
b36be3a1 | 39 | #include "mem.h" |
f640bcb3 RK |
40 | #include "macros.h" |
41 | #include "sink.h" | |
42 | #include "syscalls.h" | |
43 | #include "log.h" | |
44 | #include "wstat.h" | |
45 | #include "kvp.h" | |
b36be3a1 RK |
46 | #include "hash.h" |
47 | #include "split.h" | |
48 | #include "printf.h" | |
49 | #include "vector.h" | |
50 | ||
51 | static struct vector include_path; | |
f640bcb3 RK |
52 | |
53 | /** @brief Return 1 if @p s is 'true' else 0 */ | |
54 | int mx_str2bool(const char *s) { | |
55 | return !strcmp(s, "true"); | |
56 | } | |
57 | ||
58 | /** @brief Return "true" if @p n is nonzero else "false" */ | |
59 | const char *mx_bool2str(int n) { | |
60 | return n ? "true" : "false"; | |
61 | } | |
62 | ||
b36be3a1 RK |
63 | /** @brief Write a boolean result */ |
64 | static int mx_bool_result(struct sink *output, int result) { | |
65 | if(sink_writes(output, mx_bool2str(result)) < 0) | |
66 | return -1; | |
67 | else | |
68 | return 0; | |
69 | } | |
70 | ||
71 | /* @include{TEMPLATE} | |
72 | * | |
73 | * Includes TEMPLATE. | |
74 | * | |
75 | * TEMPLATE can be an absolute filename starting with a '/'; only the file with | |
76 | * exactly this name will be included. | |
77 | * | |
78 | * Alternatively it can be a relative filename, not starting with a '/'. In | |
79 | * this case the file will be searched for in the include path. When searching | |
80 | * paths, unreadable files are treated as if they do not exist (rather than | |
81 | * matching then producing an error). | |
f640bcb3 | 82 | * |
b36be3a1 RK |
83 | * If the name chosen ends ".tmpl" then the file will be expanded as a |
84 | * template. Anything else is included byte-for-byte without further | |
85 | * modification. | |
86 | * | |
87 | * Only regular files are allowed (no devices, sockets or name pipes). | |
f640bcb3 RK |
88 | */ |
89 | static int exp_include(int attribute((unused)) nargs, | |
b36be3a1 RK |
90 | char **args, |
91 | struct sink *output, | |
92 | void *u) { | |
93 | const char *name = args[0]; | |
94 | char *path; | |
95 | int fd, n; | |
96 | char buffer[4096]; | |
97 | struct stat sb; | |
98 | ||
99 | if(name[0] == '/') { | |
100 | if(access(name, O_RDONLY) < 0) { | |
101 | error(errno, "cannot read template %s", name); | |
102 | if(sink_printf(output, "[[cannot open template '%s']]", name) < 0) | |
103 | return -1; | |
104 | return -3; | |
105 | } | |
106 | path = xstrdup(name); | |
107 | } else { | |
108 | int n; | |
109 | ||
110 | /* Search the include path */ | |
111 | for(n = 0; n < include_path.nvec; ++n) { | |
112 | byte_xasprintf(&path, "%s/%s", include_path.vec[n], name); | |
113 | if(access(path, O_RDONLY) == 0) | |
114 | break; | |
115 | } | |
116 | if(n >= include_path.nvec) { | |
117 | error(0, "cannot find template '%s'", name); | |
118 | if(sink_printf(output, "[[cannot find template '%s']]", name) < 0) | |
119 | return -1; | |
120 | return -3; | |
121 | } | |
122 | } | |
123 | /* If it's a template expand it */ | |
124 | if(strlen(path) >= 5 && !strncmp(path + strlen(path) - 5, ".tmpl", 5)) | |
125 | return mx_expand_file(path, output, u); | |
126 | /* Read the raw file. As with mx_expand_file() we insist that the file is a | |
127 | * regular file. */ | |
128 | if((fd = open(path, O_RDONLY)) < 0) | |
129 | fatal(errno, "error opening %s", path); | |
130 | if(fstat(fd, &sb) < 0) | |
131 | fatal(errno, "error statting %s", path); | |
132 | if(!S_ISREG(sb.st_mode)) | |
133 | fatal(0, "%s: not a regular file", path); | |
134 | while((n = read(fd, buffer, sizeof buffer)) > 0) { | |
135 | if(sink_write(output, buffer, n) < 0) { | |
136 | xclose(fd); | |
137 | return -1; | |
138 | } | |
139 | } | |
140 | if(n < 0) | |
141 | fatal(errno, "error reading %s", path); | |
142 | xclose(fd); | |
143 | return 0; | |
f640bcb3 RK |
144 | } |
145 | ||
146 | /* @include{COMMAND} | |
147 | * | |
148 | * Executes COMMAND via the shell (using "sh -c") and copies its | |
149 | * standard output to the template output. The shell command output | |
150 | * is not expanded or modified in any other way. | |
151 | * | |
152 | * The shell command's standard error is copied to the error log. | |
153 | * | |
154 | * If the shell exits nonzero then this is reported to the error log | |
155 | * but otherwise no special action is taken. | |
156 | */ | |
157 | static int exp_shell(int attribute((unused)) nargs, | |
158 | char **args, | |
159 | struct sink *output, | |
160 | void attribute((unused)) *u) { | |
161 | int w, p[2], n; | |
162 | char buffer[4096]; | |
163 | pid_t pid; | |
164 | ||
165 | xpipe(p); | |
166 | if(!(pid = xfork())) { | |
167 | exitfn = _exit; | |
168 | xclose(p[0]); | |
169 | xdup2(p[1], 1); | |
170 | xclose(p[1]); | |
171 | execlp("sh", "sh", "-c", args[0], (char *)0); | |
172 | fatal(errno, "error executing sh"); | |
173 | } | |
174 | xclose(p[1]); | |
175 | while((n = read(p[0], buffer, sizeof buffer))) { | |
176 | if(n < 0) { | |
177 | if(errno == EINTR) | |
178 | continue; | |
179 | else | |
180 | fatal(errno, "error reading from pipe"); | |
181 | } | |
182 | if(output->write(output, buffer, n) < 0) | |
183 | return -1; | |
184 | } | |
185 | xclose(p[0]); | |
186 | while((n = waitpid(pid, &w, 0)) < 0 && errno == EINTR) | |
187 | ; | |
188 | if(n < 0) | |
189 | fatal(errno, "error calling waitpid"); | |
190 | if(w) | |
191 | error(0, "shell command '%s' %s", args[0], wstat(w)); | |
192 | return 0; | |
193 | } | |
194 | ||
195 | /* @if{CONDITION}{IF-TRUE}{IF-FALSE} | |
196 | * | |
197 | * If CONDITION is "true" then evaluates to IF-TRUE. Otherwise | |
198 | * evaluates to IF-FALSE. The IF-FALSE part is optional. | |
199 | */ | |
200 | static int exp_if(int nargs, | |
201 | const struct mx_node **args, | |
202 | struct sink *output, | |
203 | void *u) { | |
204 | char *s; | |
205 | int rc; | |
206 | ||
b36be3a1 | 207 | if((rc = mx_expandstr(args[0], &s, u, "argument #0 (CONDITION)"))) |
f640bcb3 RK |
208 | return rc; |
209 | if(mx_str2bool(s)) | |
210 | return mx_expand(args[1], output, u); | |
211 | else if(nargs > 2) | |
212 | return mx_expand(args[2], output, u); | |
213 | else | |
214 | return 0; | |
215 | } | |
216 | ||
217 | /* @and{BRANCH}{BRANCH}... | |
218 | * | |
219 | * Expands to "true" if all the branches are "true" otherwise to "false". If | |
220 | * there are no brances then the result is "true". Only as many branches as | |
221 | * necessary to compute the answer are evaluated (starting from the first one), | |
222 | * so if later branches have side effects they may not take place. | |
223 | */ | |
224 | static int exp_and(int nargs, | |
225 | const struct mx_node **args, | |
226 | struct sink *output, | |
227 | void *u) { | |
228 | int n, result = 1, rc; | |
b36be3a1 | 229 | char *s, *argname; |
f640bcb3 RK |
230 | |
231 | for(n = 0; n < nargs; ++n) { | |
b36be3a1 RK |
232 | byte_xasprintf(&argname, "argument #%d", n); |
233 | if((rc = mx_expandstr(args[n], &s, u, argname))) | |
f640bcb3 RK |
234 | return rc; |
235 | if(!mx_str2bool(s)) { | |
236 | result = 0; | |
237 | break; | |
238 | } | |
239 | } | |
b36be3a1 | 240 | return mx_bool_result(output, result); |
f640bcb3 RK |
241 | } |
242 | ||
243 | /* @or{BRANCH}{BRANCH}... | |
244 | * | |
245 | * Expands to "true" if any of the branches are "true" otherwise to "false". | |
246 | * If there are no brances then the result is "false". Only as many branches | |
247 | * as necessary to compute the answer are evaluated (starting from the first | |
248 | * one), so if later branches have side effects they may not take place. | |
249 | */ | |
250 | static int exp_or(int nargs, | |
251 | const struct mx_node **args, | |
252 | struct sink *output, | |
253 | void *u) { | |
254 | int n, result = 0, rc; | |
b36be3a1 | 255 | char *s, *argname; |
f640bcb3 RK |
256 | |
257 | for(n = 0; n < nargs; ++n) { | |
b36be3a1 RK |
258 | byte_xasprintf(&argname, "argument #%d", n); |
259 | if((rc = mx_expandstr(args[n], &s, u, argname))) | |
f640bcb3 RK |
260 | return rc; |
261 | if(mx_str2bool(s)) { | |
262 | result = 1; | |
263 | break; | |
264 | } | |
265 | } | |
b36be3a1 | 266 | return mx_bool_result(output, result); |
f640bcb3 RK |
267 | } |
268 | ||
269 | /* @not{CONDITION} | |
270 | * | |
271 | * Expands to "true" unless CONDITION is "true" in which case "false". | |
272 | */ | |
273 | static int exp_not(int attribute((unused)) nargs, | |
274 | char **args, | |
275 | struct sink *output, | |
276 | void attribute((unused)) *u) { | |
b36be3a1 | 277 | return mx_bool_result(output, !mx_str2bool(args[0])); |
f640bcb3 RK |
278 | } |
279 | ||
280 | /* @#{...} | |
281 | * | |
282 | * Expands to nothing. The argument(s) are not fully evaluated, and no side | |
283 | * effects occur. | |
284 | */ | |
285 | static int exp_comment(int attribute((unused)) nargs, | |
286 | const struct mx_node attribute((unused)) **args, | |
287 | struct sink attribute((unused)) *output, | |
288 | void attribute((unused)) *u) { | |
289 | return 0; | |
290 | } | |
291 | ||
292 | /* @urlquote{STRING} | |
293 | * | |
294 | * URL-quotes a string, i.e. replaces any characters not safe to use unquoted | |
295 | * in a URL with %-encoded form. | |
296 | */ | |
297 | static int exp_urlquote(int attribute((unused)) nargs, | |
298 | char **args, | |
299 | struct sink *output, | |
300 | void attribute((unused)) *u) { | |
301 | if(sink_writes(output, urlencodestring(args[0])) < 0) | |
302 | return -1; | |
303 | else | |
304 | return 0; | |
305 | } | |
306 | ||
b36be3a1 RK |
307 | /* @eq{S1}{S2}... |
308 | * | |
309 | * Expands to "true" if all the arguments are identical, otherwise to "false" | |
310 | * (i.e. if any pair of arguments differs). | |
311 | * | |
312 | * If there are no arguments then expands to "true". Evaluates all arguments | |
313 | * (with their side effects) even if that's not strictly necessary to discover | |
314 | * the result. | |
315 | */ | |
316 | static int exp_eq(int nargs, | |
317 | char **args, | |
318 | struct sink *output, | |
319 | void attribute((unused)) *u) { | |
320 | int n, result = 1; | |
321 | ||
322 | for(n = 1; n < nargs; ++n) { | |
323 | if(strcmp(args[n], args[0])) { | |
324 | result = 0; | |
325 | break; | |
326 | } | |
327 | } | |
328 | return mx_bool_result(output, result); | |
329 | } | |
330 | ||
331 | /* @ne{S1}{S2}... | |
332 | * | |
333 | * Expands to "true" if all of the arguments differ from one another, otherwise | |
334 | * to "false" (i.e. if any value appears more than once). | |
335 | * | |
336 | * If there are no arguments then expands to "true". Evaluates all arguments | |
337 | * (with their side effects) even if that's not strictly necessary to discover | |
338 | * the result. | |
339 | */ | |
340 | static int exp_ne(int nargs, | |
341 | char **args, | |
342 | struct sink *output, | |
343 | void attribute((unused))*u) { | |
344 | hash *h = hash_new(sizeof (char *)); | |
345 | int n, result = 1; | |
346 | ||
347 | for(n = 0; n < nargs; ++n) | |
348 | if(hash_add(h, args[n], "", HASH_INSERT)) { | |
349 | result = 0; | |
350 | break; | |
351 | } | |
352 | return mx_bool_result(output, result); | |
353 | } | |
354 | ||
355 | /* @discard{...} | |
356 | * | |
357 | * Expands to nothing. Unlike the comment expansion @#{...}, side effects of | |
358 | * arguments are not suppressed. So this can be used to surround a collection | |
359 | * of macro definitions with whitespace, free text commentary, etc. | |
360 | */ | |
361 | static int exp_discard(int attribute((unused)) nargs, | |
362 | char attribute((unused)) **args, | |
363 | struct sink attribute((unused)) *output, | |
364 | void attribute((unused)) *u) { | |
365 | return 0; | |
366 | } | |
367 | ||
368 | /* @define{NAME}{ARG1 ARG2...}{DEFINITION} | |
369 | * | |
370 | * Define a macro. The macro will be called NAME and will act like an | |
371 | * expansion. When it is expanded, the expansion is replaced by DEFINITION, | |
372 | * with each occurence of @ARG1@ etc replaced by the parameters to the | |
373 | * expansion. | |
374 | */ | |
375 | static int exp_define(int attribute((unused)) nargs, | |
376 | const struct mx_node **args, | |
377 | struct sink attribute((unused)) *output, | |
378 | void attribute((unused)) *u) { | |
379 | char **as, *name, *argnames; | |
380 | int rc, nas; | |
381 | ||
382 | if((rc = mx_expandstr(args[0], &name, u, "argument #0 (NAME)"))) | |
383 | return rc; | |
384 | if((rc = mx_expandstr(args[1], &argnames, u, "argument #1 (ARGS)"))) | |
385 | return rc; | |
386 | as = split(argnames, &nas, 0, 0, 0); | |
387 | mx_register_macro(name, nas, as, args[2]); | |
388 | return 0; | |
389 | } | |
390 | ||
f640bcb3 | 391 | void mx_register_builtin(void) { |
b36be3a1 RK |
392 | mx_register_magic("#", 0, INT_MAX, exp_comment); |
393 | mx_register_magic("and", 0, INT_MAX, exp_and); | |
394 | mx_register_magic("define", 3, 3, exp_define); | |
395 | mx_register_magic("if", 2, 3, exp_if); | |
396 | mx_register_magic("or", 0, INT_MAX, exp_or); | |
397 | mx_register("discard", 0, INT_MAX, exp_discard); | |
398 | mx_register("eq", 0, INT_MAX, exp_eq); | |
f640bcb3 | 399 | mx_register("include", 1, 1, exp_include); |
b36be3a1 | 400 | mx_register("ne", 0, INT_MAX, exp_ne); |
f640bcb3 | 401 | mx_register("not", 1, 1, exp_not); |
b36be3a1 | 402 | mx_register("shell", 1, 1, exp_shell); |
f640bcb3 | 403 | mx_register("urlquote", 1, 1, exp_urlquote); |
f640bcb3 RK |
404 | } |
405 | ||
406 | /* | |
407 | Local Variables: | |
408 | c-basic-offset:2 | |
409 | comment-column:40 | |
410 | fill-column:79 | |
411 | indent-tabs-mode:nil | |
412 | End: | |
413 | */ |