filter.c

   1 /*
   2  * Copyright (C) 2005-2008 Andre Noll <maan@systemlinux.org>
   3  *
   4  * Licensed under the GPL v2. For licencing details see COPYING.
   5  */
   6
   7 /** \file filter.c The stand-alone filter program. */
   8
   9 #include "para.h"
  10
  11 #include "filter.cmdline.h"
  12 #include "list.h"
  13 #include "sched.h"
  14 #include "filter.h"
  15 #include "string.h"
  16 #include "stdin.h"
  17 #include "stdout.h"
  18 #include "error.h"
  19
  20 /** Initialize the array of errors for para_filter. */
  21 INIT_FILTER_ERRLISTS;
  22
  23 /** The task that reads from stdin. */
  24 static struct stdin_task stdin_task_struct;
  25 /** pointer to the stdin task. */
  26 static struct stdin_task *sit = &stdin_task_struct;
  27
  28 /** The task that filters the data. */
  29 static struct filter_chain filter_chain_struct;
  30 /** Pointer to the filter chain. */
  31 static struct filter_chain *fc = &filter_chain_struct;
  32
  33 /** The task that writes converted data to stdout. */
  34 static struct stdout_task stdout_task_struct;
  35 /** Pointer to the stdout task. */
  36 static struct stdout_task *sot = &stdout_task_struct;
  37
  38 /** Gengetopt struct that holds the command line args. */
  39 static struct filter_args_info conf;
  40
  41 INIT_STDERR_LOGGING(conf.loglevel_arg);
  42
  43 static void open_filters(void)
  44 {
  45         int i;
  46         struct filter_node *fn;
  47
  48         FOR_EACH_FILTER_NODE(fn, fc, i) {
  49                 struct filter *f = filters + fn->filter_num;
  50                 f->open(fn);
  51                 PARA_INFO_LOG("opened %s filter\n", f->name);
  52                 fc->outbuf = fn->buf;
  53                 fc->out_loaded = &fn->loaded;
  54         }
  55 }
  56
  57 static int init_filter_chain(void)
  58 {
  59         int i, ret;
  60         struct filter_node *fn;
  61
  62         if (!conf.filter_given)
  63                 return -E_NO_FILTERS;
  64         fc->num_filters = conf.filter_given;
  65         fc->filter_nodes = para_malloc(fc->num_filters * sizeof(struct filter_node));
  66         fc->inbuf = sit->buf;
  67         fc->in_loaded = &sit->loaded;
  68         fc->input_error = &sit->task.error;
  69         fc->task.error = 0;
  70         fc->output_error = &sot->task.error;
  71         fc->task.pre_select = filter_pre_select;
  72         sprintf(fc->task.status, "filter chain");
  73
  74         FOR_EACH_FILTER_NODE(fn, fc, i) {
  75                 char *fa = conf.filter_arg[i];
  76                 fn = fc->filter_nodes + i;
  77                 ret = check_filter_arg(fa, &fn->conf);
  78                 if (ret < 0)
  79                         goto err;
  80                 fn->filter_num = ret;
  81                 fn->fc = fc;
  82                 INIT_LIST_HEAD(&fn->callbacks);
  83                 PARA_DEBUG_LOG("filter #%d: %s\n", i, filters[fn->filter_num].name);
  84         }
  85         open_filters();
  86         return 1;
  87 err:
  88         free(fc->filter_nodes);
  89         return ret;
  90 }
  91
  92 static int parse_config(int argc, char *argv[])
  93 {
  94         static char *cf; /* config file */
  95         struct stat statbuf;
  96         int i;
  97
  98         if (filter_cmdline_parser(argc, argv, &conf))
  99                 return -E_FILTER_SYNTAX;
 100         HANDLE_VERSION_FLAG("filter", conf);
 101         if (!cf) {
 102                 char *home = para_homedir();
 103                 cf = make_message("%s/.paraslash/filter.conf", home);
 104                 free(home);
 105         }
 106         if (!stat(cf, &statbuf)) {
 107                 struct filter_cmdline_parser_params params = {
 108                         .override = 0,
 109                         .initialize = 0,
 110                         .check_required = 0,
 111                         .check_ambiguity = 0
 112                 };
 113                 if (filter_cmdline_parser_config_file(cf, &conf, &params))
 114                         return -E_FILTER_SYNTAX;
 115         }
 116         if (!conf.list_filters_given)
 117                 return 1;
 118         printf("available filters: ");
 119         for (i = 0; filters[i].name; i++)
 120                 printf("%s%s%s", i? " " : "", filters[i].name,
 121                         filters[i].parse_config? "*": "");
 122         printf("\nFilters marked with \"*\" have further command line options. Try\n"
 123                 "\tpara_filter -f '<filtername> -h'\nfor more information.\n");
 124         exit(EXIT_SUCCESS);
 125 }
 126
 127 /**
 128  * The main function of para_filter.
 129  *
 130  * Para_filter reads data from stdin, converts it by using a chain
 131  * of filters (specified on the command line) and writes the resulting
 132  * data to stdout.
 133  *
 134  * \param argc Number of command line options.
 135  * \param argv Vector of arguments.
 136  *
 137  * \return \a EXIT_SUCCESS on success, EXIT_FAILURE on errors.
 138  */
 139 int main(int argc, char *argv[])
 140 {
 141         int ret;
 142         static struct sched s;
 143
 144         stdin_set_defaults(sit);
 145         sit->buf = para_malloc(sit->bufsize),
 146
 147         filter_init(filters);
 148         ret = parse_config(argc, argv);
 149         if (ret < 0)
 150                 goto out;
 151         ret = init_filter_chain();
 152         if (ret < 0)
 153                 goto out;
 154
 155         stdout_set_defaults(sot);
 156         sot->buf = fc->outbuf;
 157         sot->loaded = fc->out_loaded;
 158         sot->input_error = &fc->task.error;
 159
 160         register_task(&sit->task);
 161         register_task(&fc->task);
 162         register_task(&sot->task);
 163         s.default_timeout.tv_sec = 1;
 164         s.default_timeout.tv_usec = 0;
 165         ret = schedule(&s);
 166         close_filters(fc);
 167 out:
 168         free(sit->buf);
 169         if (ret < 0)
 170                 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
 171         return ret < 0? EXIT_FAILURE : EXIT_SUCCESS;
 172 }