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 /** \file filter.c the stand-alone filter program */
   7
   8 #include "para.h"
   9
  10 #include "filter.cmdline.h"
  11 #include "list.h"
  12 #include "sched.h"
  13 #include "filter.h"
  14 #include "string.h"
  15 #include "stdin.h"
  16 #include "stdout.h"
  17 #include "error.h"
  18
  19 /** init the array of errors for para_filter */
  20 INIT_FILTER_ERRLISTS;
  21
  22 /** the task that reads from stdin */
  23 static struct stdin_task stdin_task_struct;
  24 /** pointer to the stdin task */
  25 static struct stdin_task *sit = &stdin_task_struct;
  26
  27 /** the task that filters the data */
  28 static struct filter_chain filter_chain_struct;
  29 /** pointer to the filter chain */
  30 static struct filter_chain *fc = &filter_chain_struct;
  31
  32 /** the task that writes converted data to stdout */
  33 static struct stdout_task stdout_task_struct;
  34 /** pointer to the stdout task */
  35 static struct stdout_task *sot = &stdout_task_struct;
  36
  37 /** gengetopt struct that holds the command line args */
  38 static struct filter_args_info conf;
  39
  40 INIT_STDERR_LOGGING(conf.loglevel_arg);
  41
  42 static void filter_event_handler(struct task *t)
  43 {
  44         PARA_NOTICE_LOG("%s\n", para_strerror(-t->ret));
  45         unregister_task(t);
  46 }
  47
  48 static void open_filters(void)
  49 {
  50         struct filter_node *fn;
  51
  52         list_for_each_entry(fn, &fc->filters, node) {
  53                 fn->filter->open(fn);
  54                 PARA_INFO_LOG("opened %s filter\n", fn->filter->name);
  55                 fc->outbuf = fn->buf;
  56                 fc->out_loaded = &fn->loaded;
  57         }
  58 }
  59
  60 static int init_filter_chain(void)
  61 {
  62         int i, filter_num;
  63         struct filter_node *fn;
  64
  65         INIT_LIST_HEAD(&fc->filters);
  66
  67         fc->inbuf = sit->buf;
  68         fc->in_loaded = &sit->loaded;
  69         fc->input_error = &sit->error;
  70         fc->error = 0;
  71         fc->output_error = &sot->error;
  72         fc->task.private_data = fc;
  73         fc->task.pre_select = filter_pre_select;
  74         fc->task.event_handler = filter_event_handler;
  75         sprintf(fc->task.status, "filter chain");
  76
  77         for (i = 0; i < conf.filter_given; i++) {
  78                 char *fa = conf.filter_arg[i];
  79                 fn = para_calloc(sizeof(struct filter_node));
  80                 filter_num = check_filter_arg(fa, &fn->conf);
  81                 if (filter_num < 0) {
  82                         free(fn);
  83                         return filter_num;
  84                 }
  85                 fn->fc = fc;
  86                 INIT_LIST_HEAD(&fn->callbacks);
  87                 fn->filter = &filters[filter_num];
  88                 PARA_DEBUG_LOG("adding %s to filter chain\n", fn->filter->name);
  89                 list_add_tail(&fn->node, &fc->filters);
  90         }
  91         if (list_empty(&fc->filters))
  92                 return -E_NO_FILTERS;
  93         open_filters();
  94         return 1;
  95 }
  96
  97 static int parse_config(int argc, char *argv[])
  98 {
  99         static char *cf; /* config file */
 100         struct stat statbuf;
 101         int i;
 102
 103         if (filter_cmdline_parser(argc, argv, &conf))
 104                 return -E_FILTER_SYNTAX;
 105         HANDLE_VERSION_FLAG("filter", conf);
 106         if (!cf) {
 107                 char *home = para_homedir();
 108                 cf = make_message("%s/.paraslash/filter.conf", home);
 109                 free(home);
 110         }
 111         if (!stat(cf, &statbuf)) {
 112                 struct filter_cmdline_parser_params params = {
 113                         .override = 0,
 114                         .initialize = 0,
 115                         .check_required = 0,
 116                         .check_ambiguity = 0
 117                 };
 118                 if (filter_cmdline_parser_config_file(cf, &conf, &params))
 119                         return -E_FILTER_SYNTAX;
 120         }
 121         if (!conf.list_filters_given)
 122                 return 1;
 123         printf("available filters: ");
 124         for (i = 0; filters[i].name; i++)
 125                 printf("%s%s%s", i? " " : "", filters[i].name,
 126                         filters[i].parse_config? "*": "");
 127         printf("\nFilters marked with \"*\" have further command line options. Try\n"
 128                 "\tpara_filter -f '<filtername> -h'\nfor more information.\n");
 129         exit(EXIT_SUCCESS);
 130 }
 131
 132 /**
 133  * para_filter's main function.
 134  *
 135  * para_filter reads data from stdin, converts it by using a chain
 136  * of filters (specified on the command line) and writes the resulting
 137  * data to stdout.
 138  *
 139  * \param argc number of command line options
 140  * \param argv vector of arguments
 141  *
 142  * \return \a EXIT_SUCCESS on success, EXIT_FAILURE on errors.
 143  */
 144 int main(int argc, char *argv[])
 145 {
 146         int ret;
 147         struct sched s;
 148
 149         stdin_set_defaults(sit);
 150         sit->buf = para_malloc(sit->bufsize),
 151
 152         filter_init(filters);
 153         ret = parse_config(argc, argv);
 154         if (ret < 0)
 155                 goto out;
 156         ret = init_filter_chain();
 157         if (ret < 0)
 158                 goto out;
 159
 160         stdout_set_defaults(sot);
 161         sot->buf = fc->outbuf;
 162         sot->loaded = fc->out_loaded;
 163         sot->input_error = &fc->error;
 164
 165         register_task(&sit->task);
 166         register_task(&fc->task);
 167         register_task(&sot->task);
 168         s.default_timeout.tv_sec = 1;
 169         s.default_timeout.tv_usec = 0;
 170         ret = schedule(&s);
 171 out:
 172         free(sit->buf);
 173         close_filters(fc);
 174         if (ret < 0)
 175                 PARA_EMERG_LOG("%s\n", para_strerror(-ret));
 176         return ret < 0? EXIT_FAILURE : EXIT_SUCCESS;
 177 }