doxify para_filter
[paraslash.git] / filter.c
1 /*
2 * Copyright (C) 2005-2007 Andre Noll <maan@systemlinux.org>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111, USA.
17 */
18 /** \file filter.c the stand-alone filter program */
19
20 #include "para.h"
21
22 #include "filter.cmdline.h"
23 #include "list.h"
24 #include "sched.h"
25 #include "filter.h"
26 #include "string.h"
27 #include "stdin.h"
28 #include "stdout.h"
29 #include "error.h"
30
31 /** init the array of errors for para_filter */
32 INIT_FILTER_ERRLISTS;
33
34 /** the task that reads from stdin */
35 static struct stdin_task stdin_task_struct;
36 /** pointer to the stdin task */
37 static struct stdin_task *sit = &stdin_task_struct;
38
39 /** the task that filters the data */
40 static struct filter_chain filter_chain_struct;
41 /** pointer to the filter chain */
42 static struct filter_chain *fc = &filter_chain_struct;
43
44 /** the task that writes converted data to stdout */
45 static struct stdout_task stdout_task_struct;
46 /** pointer to the stdout task */
47 static struct stdout_task *sot = &stdout_task_struct;
48
49 /** gengetopt struct that holds the command line args */
50 static struct filter_args_info conf;
51
52
53 /**
54 * standard log function that always writes to stderr
55 *
56 * \param ll loglevel. If the loglevel of the current message
57 * is less than \a ll, the message is going to be ignored.
58 *
59 * \param fmt the format string describing the log message.
60 *
61 */
62 __printf_2_3 void para_log(int ll, const char* fmt,...)
63 {
64 va_list argp;
65
66 /* ignore log message if loglevel is not high enough */
67 if (ll < conf.loglevel_arg)
68 return;
69 va_start(argp, fmt);
70 vfprintf(stderr, fmt, argp);
71 va_end(argp);
72 }
73
74 static void filter_event_handler(struct task *t)
75 {
76 PARA_NOTICE_LOG("%s\n", PARA_STRERROR(-t->ret));
77 unregister_task(t);
78 }
79
80 static void open_filters(void)
81 {
82 struct filter_node *fn;
83
84 list_for_each_entry(fn, &fc->filters, node) {
85 fn->filter->open(fn);
86 PARA_INFO_LOG("opened %s filter\n", fn->filter->name);
87 fc->outbuf = fn->buf;
88 fc->out_loaded = &fn->loaded;
89 }
90 }
91
92 static int init_filter_chain(void)
93 {
94 int i, filter_num;
95 struct filter_node *fn;
96
97 INIT_LIST_HEAD(&fc->filters);
98
99 fc->inbuf = sit->buf;
100 fc->in_loaded = &sit->loaded;
101 fc->input_eof = &sit->eof;
102 fc->eof = 0;
103 fc->output_eof = &sot->eof;
104 fc->task.private_data = fc;
105 fc->task.pre_select = filter_pre_select;
106 fc->task.event_handler = filter_event_handler;
107 sprintf(fc->task.status, "filter chain");
108
109 for (i = 0; i < conf.filter_given; i++) {
110 char *fa = conf.filter_arg[i];
111 fn = para_calloc(sizeof(struct filter_node));
112 filter_num = check_filter_arg(fa, &fn->conf);
113 if (filter_num < 0) {
114 free(fn);
115 return filter_num;
116 }
117 fn->fc = fc;
118 INIT_LIST_HEAD(&fn->callbacks);
119 fn->filter = &filters[filter_num];
120 PARA_DEBUG_LOG("adding %s to filter chain\n", fn->filter->name);
121 list_add_tail(&fn->node, &fc->filters);
122 }
123 if (list_empty(&fc->filters))
124 return -E_NO_FILTERS;
125 open_filters();
126 return 1;
127 }
128
129 static int parse_config(int argc, char *argv[])
130 {
131 static char *cf; /* config file */
132 struct stat statbuf;
133 int i;
134
135 if (filter_cmdline_parser(argc, argv, &conf))
136 return -E_FILTER_SYNTAX;
137 if (!cf) {
138 char *home = para_homedir();
139 cf = make_message("%s/.paraslash/filter.conf", home);
140 free(home);
141 }
142 if (!stat(cf, &statbuf)) {
143 if (filter_cmdline_parser_configfile(cf, &conf, 0, 0, 0))
144 return -E_FILTER_SYNTAX;
145 }
146 if (!conf.list_filters_given)
147 return 1;
148 printf("available filters: ");
149 for (i = 0; filters[i].name; i++)
150 printf("%s%s%s", i? " " : "", filters[i].name,
151 filters[i].parse_config? "*": "");
152 printf("\nFilters marked with \"*\" have further command line options. Try\n"
153 "\tpara_filter -f '<filtername> -h'\nfor more information.\n");
154 exit(EXIT_SUCCESS);
155 }
156
157 /**
158 * para_filter's main function.
159 *
160 * para_filter reads data from stdin, converts it by using a chain
161 * of filters (specified on the command line) and writes the resulting
162 * data to stdout.
163 *
164 * \param argc number of command line options
165 * \param argv vector of arguments
166 *
167 * \return \a EXIT_SUCCESS on success, EXIT_FAILURE on errors.
168 */
169 int main(int argc, char *argv[])
170 {
171 int ret;
172 struct sched s;
173
174 stdin_set_defaults(sit);
175 sit->buf = para_malloc(sit->bufsize),
176
177 filter_init(filters);
178 ret = parse_config(argc, argv);
179 if (ret < 0)
180 goto out;
181 ret = init_filter_chain();
182 if (ret < 0)
183 goto out;
184
185 stdout_set_defaults(sot);
186 sot->buf = fc->outbuf;
187 sot->loaded = fc->out_loaded;
188 sot->input_eof = &fc->eof;
189
190 register_task(&sot->task);
191 register_task(&fc->task);
192 register_task(&sit->task);
193 s.default_timeout.tv_sec = 1;
194 s.default_timeout.tv_usec = 0;
195 ret = sched(&s);
196 out:
197 free(sit->buf);
198 close_filters(fc);
199 if (ret < 0)
200 PARA_EMERG_LOG("%s\n", PARA_STRERROR(-ret));
201 return ret < 0? EXIT_FAILURE : EXIT_SUCCESS;
202 }