nobug_env.c

   1 /*
   2     nobug_env.c - a small debugging library
   3
   4   Copyright (C) 2007, Christian Thaeter <ct@pipapo.org>
   5
   6   This program is free software; you can redistribute it and/or modify
   7   it under the terms of the GNU General Public License version 2 as
   8   published by the Free Software Foundation.
   9
  10   This program is distributed in the hope that it will be useful,
  11   but WITHOUT ANY WARRANTY; without even the implied warranty of
  12   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13   GNU General Public License for more details.
  14
  15   You should have received a copy of the GNU General Public License
  16   along with this program; if not, contact me.
  17
  18 */
  19 #define NOBUG_LIBNOBUG_C
  20 #include "nobug.h"
  21
  22 /*
  23   Env variable parsing
  24 */
  25
  26 /*
  27   Syntax:
  28
  29   logdecl_list --> logdecl, any( ',' logdecl_list)
  30   logdecl --> flag, opt(limitdecl, any(targetdecl))
  31   flag --> "identifier of a flag"
  32   limitdecl --> ':', "LIMITNAME"
  33   targetdecl --> '@', "targetname", opt(targetopts)
  34   targetopts --> '(', "options for target", ')', opt(targetopts)
  35
  36   examples:
  37   NOBUG_LOG='flag,other'                        # set the limit of the 'default' target a default limit
  38   NOBUG_LOG='flag:DEBUG'                        # set the limit of the 'default' target to DEBUG
  39   NOBUG_LOG='flag:DEBUG@console@syslog'         # set console and syslog limits for flag to DEBUG
  40   NOBUG_LOG='flag:DEBUG,other:TRACE@ringbuffer'
  41
  42   TODO:
  43   (options) on targets are not yet implemented
  44
  45 */
  46
  47 const struct
  48 {
  49   const char * name;
  50   int value;
  51 } nobug_limits[] =
  52   {
  53     ":EMERG", LOG_EMERG,
  54     ":ALERT", LOG_ALERT,
  55     ":CRIT", LOG_CRIT,
  56     ":ERR", LOG_ERR,
  57     ":ERROR", LOG_ERR,
  58     ":WARNING", LOG_WARNING,
  59     ":WARN", LOG_WARNING,
  60     ":NOTICE", LOG_NOTICE,
  61     ":INFO", LOG_INFO,
  62     ":DEBUG", LOG_DEBUG,
  63     ":TRACE", LOG_DEBUG,
  64   };
  65
  66 const char* nobug_targets[] =
  67   {"@ringbuffer", "@console", "@file", "@syslog", "@application"};
  68
  69
  70 void
  71 nobug_env_parse_flag (const char* env, struct nobug_flag* flag, int default_target, int default_limit)
  72 {
  73   size_t flaglen = strlen (flag->name);
  74   if (!env || !flag->name)
  75     return;
  76
  77   do
  78     {
  79       if (!strncmp(env, flag->name, flaglen))
  80         {
  81           /* flagname matches */
  82           int limit;
  83           env += flaglen;
  84           if (*env == ':')
  85             for (limit = 0; limit<11; ++limit)
  86               {
  87                 size_t limitlen = strlen (nobug_limits[limit].name);
  88                 if (!strncmp(env, nobug_limits[limit].name, limitlen))
  89                   {
  90                     /* found :LIMIT */
  91                     int target;
  92                     env += limitlen;
  93                     if (*env == '@')
  94                       while (*env == '@')
  95                         {
  96                           for (target = 0; target<5; ++target)
  97                             {
  98                               size_t targetlen = strlen (nobug_targets[target]);
  99                               if (!strncmp(env, nobug_targets[target], targetlen))
 100                                 {
 101                                   /* @target found */
 102                                   env += targetlen;
 103                                   /* TODO target options are unimplemented
 104                                      switch (target)
 105                                      {
 106                                      case NOBUG_TARGET_RINGBUFFER:
 107                                      // filename flags size
 108                                      case NOBUG_TARGET_CONSOLE:
 109                                      //  FILE*
 110                                      case NOBUG_TARGET_FILE:
 111                                      // filename flags
 112                                      case NOBUG_TARGET_SYSLOG:
 113                                      // facility options prefix
 114                                      case NOBUG_TARGET_APPLICATION:
 115                                      }
 116                                   */
 117                                   flag->limits[target] = nobug_limits[limit].value;
 118                                 }
 119                             }
 120                         }
 121                     else
 122                       {
 123                         /* flag:LIMIT with no @target */
 124                         flag->limits[default_target] = nobug_limits[limit].value;
 125                       }
 126                   }
 127               }
 128           else
 129             {
 130               /* flag with no :LIMIT */
 131               flag->limits[default_target] = default_limit;
 132             }
 133         }
 134       env = strchr(env, ',');
 135       if (env)
 136         ++env;
 137     }
 138   while (env);
 139 }
 140
 141
 142 void
 143 nobug_env_init_flag (struct nobug_flag* flag, int default_target, int default_limit)
 144 {
 145   nobug_init();
 146
 147   /* set some defaults */
 148   flag->ringbuffer_target = nobug_default_ringbuffer;
 149   flag->console_target = stderr;
 150   flag->file_target = nobug_default_file;
 151
 152   /* parse $NOBUG_LOG */
 153   nobug_env_parse_flag (getenv("NOBUG_LOG"), flag, default_target, default_limit);
 154
 155   /* ensure that the ringbuffer is the most verbose */
 156   int i;
 157   int max;
 158
 159   for (i = NOBUG_TARGET_CONSOLE; i <= NOBUG_TARGET_APPLICATION; ++i)
 160     {
 161       max = max > flag->limits[i] ? max : flag->limits[i];
 162     }
 163
 164   flag->limits[NOBUG_TARGET_RINGBUFFER] = max > flag->limits[NOBUG_TARGET_RINGBUFFER]
 165     ? max : flag->limits[NOBUG_TARGET_RINGBUFFER];
 166 }