chiark / gitweb /
infer_url() now attempts to spot https
[disorder] / lib / macros-builtin.c
CommitLineData
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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 *
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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.
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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>
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36#include <fcntl.h>
37#include <sys/stat.h>
c240ff9a 38#include <sys/wait.h>
f640bcb3 39
9faa7a88 40#include "hash.h"
b36be3a1 41#include "mem.h"
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42#include "macros.h"
43#include "sink.h"
44#include "syscalls.h"
45#include "log.h"
46#include "wstat.h"
47#include "kvp.h"
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48#include "split.h"
49#include "printf.h"
50#include "vector.h"
51
52static struct vector include_path;
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53
54/** @brief Return 1 if @p s is 'true' else 0 */
55int mx_str2bool(const char *s) {
56 return !strcmp(s, "true");
57}
58
59/** @brief Return "true" if @p n is nonzero else "false" */
60const char *mx_bool2str(int n) {
61 return n ? "true" : "false";
62}
63
b36be3a1 64/** @brief Write a boolean result */
71634563 65int mx_bool_result(struct sink *output, int result) {
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66 if(sink_writes(output, mx_bool2str(result)) < 0)
67 return -1;
68 else
69 return 0;
70}
71
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72/** @brief Search the include path */
73char *mx_find(const char *name) {
74 char *path;
75 int n;
76
77 if(name[0] == '/') {
78 if(access(name, O_RDONLY) < 0) {
79 error(errno, "cannot read %s", name);
80 return 0;
81 }
82 path = xstrdup(name);
83 } else {
84 /* Search the include path */
85 for(n = 0; n < include_path.nvec; ++n) {
86 byte_xasprintf(&path, "%s/%s", include_path.vec[n], name);
87 if(access(path, O_RDONLY) == 0)
88 break;
89 }
90 if(n >= include_path.nvec) {
91 error(0, "cannot find '%s' in search path", name);
92 return 0;
93 }
94 }
95 return path;
96}
97
98/* @include{TEMPLATE}@
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99 *
100 * Includes TEMPLATE.
101 *
102 * TEMPLATE can be an absolute filename starting with a '/'; only the file with
103 * exactly this name will be included.
104 *
105 * Alternatively it can be a relative filename, not starting with a '/'. In
106 * this case the file will be searched for in the include path. When searching
107 * paths, unreadable files are treated as if they do not exist (rather than
108 * matching then producing an error).
f640bcb3 109 *
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110 * If the name chosen ends ".tmpl" then the file will be expanded as a
111 * template. Anything else is included byte-for-byte without further
112 * modification.
113 *
114 * Only regular files are allowed (no devices, sockets or name pipes).
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115 */
116static int exp_include(int attribute((unused)) nargs,
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117 char **args,
118 struct sink *output,
119 void *u) {
9faa7a88 120 const char *path;
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121 int fd, n;
122 char buffer[4096];
123 struct stat sb;
b36be3a1 124
9faa7a88 125 if(!(path = mx_find(args[0]))) {
f5fdc06f 126 if(sink_printf(output, "[[cannot find '%s']]", args[0]) < 0)
dd0f422a 127 return 0;
9faa7a88 128 return 0;
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129 }
130 /* If it's a template expand it */
131 if(strlen(path) >= 5 && !strncmp(path + strlen(path) - 5, ".tmpl", 5))
132 return mx_expand_file(path, output, u);
133 /* Read the raw file. As with mx_expand_file() we insist that the file is a
134 * regular file. */
135 if((fd = open(path, O_RDONLY)) < 0)
136 fatal(errno, "error opening %s", path);
137 if(fstat(fd, &sb) < 0)
138 fatal(errno, "error statting %s", path);
139 if(!S_ISREG(sb.st_mode))
140 fatal(0, "%s: not a regular file", path);
141 while((n = read(fd, buffer, sizeof buffer)) > 0) {
142 if(sink_write(output, buffer, n) < 0) {
143 xclose(fd);
144 return -1;
145 }
146 }
147 if(n < 0)
148 fatal(errno, "error reading %s", path);
149 xclose(fd);
150 return 0;
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151}
152
9faa7a88 153/* @include{COMMAND}@
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154 *
155 * Executes COMMAND via the shell (using "sh -c") and copies its
156 * standard output to the template output. The shell command output
157 * is not expanded or modified in any other way.
158 *
159 * The shell command's standard error is copied to the error log.
160 *
161 * If the shell exits nonzero then this is reported to the error log
162 * but otherwise no special action is taken.
163 */
164static int exp_shell(int attribute((unused)) nargs,
165 char **args,
166 struct sink *output,
167 void attribute((unused)) *u) {
168 int w, p[2], n;
169 char buffer[4096];
170 pid_t pid;
171
172 xpipe(p);
173 if(!(pid = xfork())) {
174 exitfn = _exit;
175 xclose(p[0]);
176 xdup2(p[1], 1);
177 xclose(p[1]);
178 execlp("sh", "sh", "-c", args[0], (char *)0);
179 fatal(errno, "error executing sh");
180 }
181 xclose(p[1]);
182 while((n = read(p[0], buffer, sizeof buffer))) {
183 if(n < 0) {
184 if(errno == EINTR)
185 continue;
186 else
187 fatal(errno, "error reading from pipe");
188 }
189 if(output->write(output, buffer, n) < 0)
190 return -1;
191 }
192 xclose(p[0]);
193 while((n = waitpid(pid, &w, 0)) < 0 && errno == EINTR)
194 ;
195 if(n < 0)
196 fatal(errno, "error calling waitpid");
197 if(w)
198 error(0, "shell command '%s' %s", args[0], wstat(w));
199 return 0;
200}
201
9faa7a88 202/* @if{CONDITION}{IF-TRUE}{IF-FALSE}@
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203 *
204 * If CONDITION is "true" then evaluates to IF-TRUE. Otherwise
205 * evaluates to IF-FALSE. The IF-FALSE part is optional.
206 */
207static int exp_if(int nargs,
208 const struct mx_node **args,
209 struct sink *output,
210 void *u) {
211 char *s;
212 int rc;
213
b36be3a1 214 if((rc = mx_expandstr(args[0], &s, u, "argument #0 (CONDITION)")))
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215 return rc;
216 if(mx_str2bool(s))
217 return mx_expand(args[1], output, u);
218 else if(nargs > 2)
219 return mx_expand(args[2], output, u);
220 else
221 return 0;
222}
223
9faa7a88 224/* @and{BRANCH}{BRANCH}...@
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225 *
226 * Expands to "true" if all the branches are "true" otherwise to "false". If
227 * there are no brances then the result is "true". Only as many branches as
228 * necessary to compute the answer are evaluated (starting from the first one),
229 * so if later branches have side effects they may not take place.
230 */
231static int exp_and(int nargs,
232 const struct mx_node **args,
233 struct sink *output,
234 void *u) {
235 int n, result = 1, rc;
b36be3a1 236 char *s, *argname;
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237
238 for(n = 0; n < nargs; ++n) {
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239 byte_xasprintf(&argname, "argument #%d", n);
240 if((rc = mx_expandstr(args[n], &s, u, argname)))
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241 return rc;
242 if(!mx_str2bool(s)) {
243 result = 0;
244 break;
245 }
246 }
b36be3a1 247 return mx_bool_result(output, result);
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248}
249
9faa7a88 250/* @or{BRANCH}{BRANCH}...@
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251 *
252 * Expands to "true" if any of the branches are "true" otherwise to "false".
253 * If there are no brances then the result is "false". Only as many branches
254 * as necessary to compute the answer are evaluated (starting from the first
255 * one), so if later branches have side effects they may not take place.
256 */
257static int exp_or(int nargs,
258 const struct mx_node **args,
259 struct sink *output,
260 void *u) {
261 int n, result = 0, rc;
b36be3a1 262 char *s, *argname;
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263
264 for(n = 0; n < nargs; ++n) {
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265 byte_xasprintf(&argname, "argument #%d", n);
266 if((rc = mx_expandstr(args[n], &s, u, argname)))
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267 return rc;
268 if(mx_str2bool(s)) {
269 result = 1;
270 break;
271 }
272 }
b36be3a1 273 return mx_bool_result(output, result);
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274}
275
9faa7a88 276/* @not{CONDITION}@
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277 *
278 * Expands to "true" unless CONDITION is "true" in which case "false".
279 */
280static int exp_not(int attribute((unused)) nargs,
281 char **args,
282 struct sink *output,
283 void attribute((unused)) *u) {
b36be3a1 284 return mx_bool_result(output, !mx_str2bool(args[0]));
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285}
286
9faa7a88 287/* @#{...}@
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288 *
289 * Expands to nothing. The argument(s) are not fully evaluated, and no side
290 * effects occur.
291 */
292static int exp_comment(int attribute((unused)) nargs,
293 const struct mx_node attribute((unused)) **args,
294 struct sink attribute((unused)) *output,
295 void attribute((unused)) *u) {
296 return 0;
297}
298
9faa7a88 299/* @urlquote{STRING}@
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300 *
301 * URL-quotes a string, i.e. replaces any characters not safe to use unquoted
302 * in a URL with %-encoded form.
303 */
304static int exp_urlquote(int attribute((unused)) nargs,
305 char **args,
306 struct sink *output,
307 void attribute((unused)) *u) {
308 if(sink_writes(output, urlencodestring(args[0])) < 0)
309 return -1;
310 else
311 return 0;
312}
313
9faa7a88 314/* @eq{S1}{S2}...@
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315 *
316 * Expands to "true" if all the arguments are identical, otherwise to "false"
317 * (i.e. if any pair of arguments differs).
318 *
319 * If there are no arguments then expands to "true". Evaluates all arguments
320 * (with their side effects) even if that's not strictly necessary to discover
321 * the result.
322 */
323static int exp_eq(int nargs,
324 char **args,
325 struct sink *output,
326 void attribute((unused)) *u) {
327 int n, result = 1;
328
329 for(n = 1; n < nargs; ++n) {
330 if(strcmp(args[n], args[0])) {
331 result = 0;
332 break;
333 }
334 }
335 return mx_bool_result(output, result);
336}
337
9faa7a88 338/* @ne{S1}{S2}...@
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339 *
340 * Expands to "true" if all of the arguments differ from one another, otherwise
341 * to "false" (i.e. if any value appears more than once).
342 *
343 * If there are no arguments then expands to "true". Evaluates all arguments
344 * (with their side effects) even if that's not strictly necessary to discover
345 * the result.
346 */
347static int exp_ne(int nargs,
348 char **args,
349 struct sink *output,
350 void attribute((unused))*u) {
351 hash *h = hash_new(sizeof (char *));
352 int n, result = 1;
353
354 for(n = 0; n < nargs; ++n)
355 if(hash_add(h, args[n], "", HASH_INSERT)) {
356 result = 0;
357 break;
358 }
359 return mx_bool_result(output, result);
360}
361
9faa7a88 362/* @discard{...}@
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363 *
364 * Expands to nothing. Unlike the comment expansion @#{...}, side effects of
365 * arguments are not suppressed. So this can be used to surround a collection
366 * of macro definitions with whitespace, free text commentary, etc.
367 */
368static int exp_discard(int attribute((unused)) nargs,
369 char attribute((unused)) **args,
370 struct sink attribute((unused)) *output,
371 void attribute((unused)) *u) {
372 return 0;
373}
374
9faa7a88 375/* @define{NAME}{ARG1 ARG2...}{DEFINITION}@
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376 *
377 * Define a macro. The macro will be called NAME and will act like an
378 * expansion. When it is expanded, the expansion is replaced by DEFINITION,
379 * with each occurence of @ARG1@ etc replaced by the parameters to the
380 * expansion.
381 */
382static int exp_define(int attribute((unused)) nargs,
383 const struct mx_node **args,
384 struct sink attribute((unused)) *output,
385 void attribute((unused)) *u) {
386 char **as, *name, *argnames;
387 int rc, nas;
388
389 if((rc = mx_expandstr(args[0], &name, u, "argument #0 (NAME)")))
390 return rc;
391 if((rc = mx_expandstr(args[1], &argnames, u, "argument #1 (ARGS)")))
392 return rc;
393 as = split(argnames, &nas, 0, 0, 0);
394 mx_register_macro(name, nas, as, args[2]);
395 return 0;
396}
397
dd0f422a 398/** @brief Register built-in expansions */
f640bcb3 399void mx_register_builtin(void) {
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400 mx_register_magic("#", 0, INT_MAX, exp_comment);
401 mx_register_magic("and", 0, INT_MAX, exp_and);
402 mx_register_magic("define", 3, 3, exp_define);
403 mx_register_magic("if", 2, 3, exp_if);
404 mx_register_magic("or", 0, INT_MAX, exp_or);
405 mx_register("discard", 0, INT_MAX, exp_discard);
406 mx_register("eq", 0, INT_MAX, exp_eq);
f640bcb3 407 mx_register("include", 1, 1, exp_include);
b36be3a1 408 mx_register("ne", 0, INT_MAX, exp_ne);
f640bcb3 409 mx_register("not", 1, 1, exp_not);
b36be3a1 410 mx_register("shell", 1, 1, exp_shell);
f640bcb3 411 mx_register("urlquote", 1, 1, exp_urlquote);
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412}
413
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414/** @brief Add a directory to the search path
415 * @param s Directory to add
416 */
417void mx_search_path(const char *s) {
418 vector_append(&include_path, xstrdup(s));
419}
420
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421/*
422Local Variables:
423c-basic-offset:2
424comment-column:40
425fill-column:79
426indent-tabs-mode:nil
427End:
428*/