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 INIT_STDERR_LOGGING(conf.loglevel_arg);
  53
  54 static void filter_event_handler(struct task *t)
  55 {
  56         PARA_NOTICE_LOG("%s\n", PARA_STRERROR(-t->ret));
  57         unregister_task(t);
  58 }
  59
  60 static void open_filters(void)
  61 {
  62         struct filter_node *fn;
  63
  64         list_for_each_entry(fn, &fc->filters, node) {
  65                 fn->filter->open(fn);
  66                 PARA_INFO_LOG("opened %s filter\n", fn->filter->name);
  67                 fc->outbuf = fn->buf;
  68                 fc->out_loaded = &fn->loaded;
  69         }
  70 }
  71
  72 static int init_filter_chain(void)
  73 {
  74         int i, filter_num;
  75         struct filter_node *fn;
  76
  77         INIT_LIST_HEAD(&fc->filters);
  78
  79         fc->inbuf = sit->buf;
  80         fc->in_loaded = &sit->loaded;
  81         fc->input_eof = &sit->eof;
  82         fc->eof = 0;
  83         fc->output_eof = &sot->eof;
  84         fc->task.private_data = fc;
  85         fc->task.pre_select = filter_pre_select;
  86         fc->task.event_handler = filter_event_handler;
  87         sprintf(fc->task.status, "filter chain");
  88
  89         for (i = 0; i < conf.filter_given; i++) {
  90                 char *fa = conf.filter_arg[i];
  91                 fn = para_calloc(sizeof(struct filter_node));
  92                 filter_num = check_filter_arg(fa, &fn->conf);
  93                 if (filter_num < 0) {
  94                         free(fn);
  95                         return filter_num;
  96                 }
  97                 fn->fc = fc;
  98                 INIT_LIST_HEAD(&fn->callbacks);
  99                 fn->filter = &filters[filter_num];
 100                 PARA_DEBUG_LOG("adding %s to filter chain\n", fn->filter->name);
 101                 list_add_tail(&fn->node, &fc->filters);
 102         }
 103         if (list_empty(&fc->filters))
 104                 return -E_NO_FILTERS;
 105         open_filters();
 106         return 1;
 107 }
 108
 109 static int parse_config(int argc, char *argv[])
 110 {
 111         static char *cf; /* config file */
 112         struct stat statbuf;
 113         int i;
 114
 115         if (filter_cmdline_parser(argc, argv, &conf))
 116                 return -E_FILTER_SYNTAX;
 117         HANDLE_VERSION_FLAG("filter", conf);
 118         if (!cf) {
 119                 char *home = para_homedir();
 120                 cf = make_message("%s/.paraslash/filter.conf", home);
 121                 free(home);
 122         }
 123         if (!stat(cf, &statbuf)) {
 124                 if (filter_cmdline_parser_configfile(cf, &conf, 0, 0, 0))
 125                         return -E_FILTER_SYNTAX;
 126         }
 127         if (!conf.list_filters_given)
 128                 return 1;
 129         printf("available filters: ");
 130         for (i = 0; filters[i].name; i++)
 131                 printf("%s%s%s", i? " " : "", filters[i].name,
 132                         filters[i].parse_config? "*": "");
 133         printf("\nFilters marked with \"*\" have further command line options. Try\n"
 134                 "\tpara_filter -f '<filtername> -h'\nfor more information.\n");
 135         exit(EXIT_SUCCESS);
 136 }
 137
 138 /**
 139  * para_filter's main function.
 140  *
 141  * para_filter reads data from stdin, converts it by using a chain
 142  * of filters (specified on the command line) and writes the resulting
 143  * data to stdout.
 144  *
 145  * \param argc number of command line options
 146  * \param argv vector of arguments
 147  *
 148  * \return \a EXIT_SUCCESS on success, EXIT_FAILURE on errors.
 149  */
 150 int main(int argc, char *argv[])
 151 {
 152         int ret;
 153         struct sched s;
 154
 155         stdin_set_defaults(sit);
 156         sit->buf = para_malloc(sit->bufsize),
 157
 158         filter_init(filters);
 159         ret = parse_config(argc, argv);
 160         if (ret < 0)
 161                 goto out;
 162         ret = init_filter_chain();
 163         if (ret < 0)
 164                 goto out;
 165
 166         stdout_set_defaults(sot);
 167         sot->buf = fc->outbuf;
 168         sot->loaded = fc->out_loaded;
 169         sot->input_eof = &fc->eof;
 170
 171         register_task(&sit->task);
 172         register_task(&fc->task);
 173         register_task(&sot->task);
 174         s.default_timeout.tv_sec = 1;
 175         s.default_timeout.tv_usec = 0;
 176         ret = sched(&s);
 177 out:
 178         free(sit->buf);
 179         close_filters(fc);
 180         if (ret < 0)
 181                 PARA_EMERG_LOG("%s\n", PARA_STRERROR(-ret));
 182         return ret < 0? EXIT_FAILURE : EXIT_SUCCESS;
 183 }