2 * This file is part of DisOrder
3 * Copyright (C) 2008 Richard Kettlewell
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.
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.
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
21 /** @file lib/macros-builtin.c
22 * @brief Built-in expansions
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.
51 static struct vector include_path;
53 /** @brief Return 1 if @p s is 'true' else 0 */
54 int mx_str2bool(const char *s) {
55 return !strcmp(s, "true");
58 /** @brief Return "true" if @p n is nonzero else "false" */
59 const char *mx_bool2str(int n) {
60 return n ? "true" : "false";
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)
75 * TEMPLATE can be an absolute filename starting with a '/'; only the file with
76 * exactly this name will be included.
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).
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
87 * Only regular files are allowed (no devices, sockets or name pipes).
89 static int exp_include(int attribute((unused)) nargs,
93 const char *name = args[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)
106 path = xstrdup(name);
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)
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)
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
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) {
141 fatal(errno, "error reading %s", path);
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.
152 * The shell command's standard error is copied to the error log.
154 * If the shell exits nonzero then this is reported to the error log
155 * but otherwise no special action is taken.
157 static int exp_shell(int attribute((unused)) nargs,
160 void attribute((unused)) *u) {
166 if(!(pid = xfork())) {
171 execlp("sh", "sh", "-c", args[0], (char *)0);
172 fatal(errno, "error executing sh");
175 while((n = read(p[0], buffer, sizeof buffer))) {
180 fatal(errno, "error reading from pipe");
182 if(output->write(output, buffer, n) < 0)
186 while((n = waitpid(pid, &w, 0)) < 0 && errno == EINTR)
189 fatal(errno, "error calling waitpid");
191 error(0, "shell command '%s' %s", args[0], wstat(w));
195 /* @if{CONDITION}{IF-TRUE}{IF-FALSE}
197 * If CONDITION is "true" then evaluates to IF-TRUE. Otherwise
198 * evaluates to IF-FALSE. The IF-FALSE part is optional.
200 static int exp_if(int nargs,
201 const struct mx_node **args,
207 if((rc = mx_expandstr(args[0], &s, u, "argument #0 (CONDITION)")))
210 return mx_expand(args[1], output, u);
212 return mx_expand(args[2], output, u);
217 /* @and{BRANCH}{BRANCH}...
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.
224 static int exp_and(int nargs,
225 const struct mx_node **args,
228 int n, result = 1, rc;
231 for(n = 0; n < nargs; ++n) {
232 byte_xasprintf(&argname, "argument #%d", n);
233 if((rc = mx_expandstr(args[n], &s, u, argname)))
235 if(!mx_str2bool(s)) {
240 return mx_bool_result(output, result);
243 /* @or{BRANCH}{BRANCH}...
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.
250 static int exp_or(int nargs,
251 const struct mx_node **args,
254 int n, result = 0, rc;
257 for(n = 0; n < nargs; ++n) {
258 byte_xasprintf(&argname, "argument #%d", n);
259 if((rc = mx_expandstr(args[n], &s, u, argname)))
266 return mx_bool_result(output, result);
271 * Expands to "true" unless CONDITION is "true" in which case "false".
273 static int exp_not(int attribute((unused)) nargs,
276 void attribute((unused)) *u) {
277 return mx_bool_result(output, !mx_str2bool(args[0]));
282 * Expands to nothing. The argument(s) are not fully evaluated, and no side
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) {
294 * URL-quotes a string, i.e. replaces any characters not safe to use unquoted
295 * in a URL with %-encoded form.
297 static int exp_urlquote(int attribute((unused)) nargs,
300 void attribute((unused)) *u) {
301 if(sink_writes(output, urlencodestring(args[0])) < 0)
309 * Expands to "true" if all the arguments are identical, otherwise to "false"
310 * (i.e. if any pair of arguments differs).
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
316 static int exp_eq(int nargs,
319 void attribute((unused)) *u) {
322 for(n = 1; n < nargs; ++n) {
323 if(strcmp(args[n], args[0])) {
328 return mx_bool_result(output, result);
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).
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
340 static int exp_ne(int nargs,
343 void attribute((unused))*u) {
344 hash *h = hash_new(sizeof (char *));
347 for(n = 0; n < nargs; ++n)
348 if(hash_add(h, args[n], "", HASH_INSERT)) {
352 return mx_bool_result(output, result);
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.
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) {
368 /* @define{NAME}{ARG1 ARG2...}{DEFINITION}
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
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;
382 if((rc = mx_expandstr(args[0], &name, u, "argument #0 (NAME)")))
384 if((rc = mx_expandstr(args[1], &argnames, u, "argument #1 (ARGS)")))
386 as = split(argnames, &nas, 0, 0, 0);
387 mx_register_macro(name, nas, as, args[2]);
391 void mx_register_builtin(void) {
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);
399 mx_register("include", 1, 1, exp_include);
400 mx_register("ne", 0, INT_MAX, exp_ne);
401 mx_register("not", 1, 1, exp_not);
402 mx_register("shell", 1, 1, exp_shell);
403 mx_register("urlquote", 1, 1, exp_urlquote);