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 int
  71 nobug_env_parse_flag (const char* env, struct nobug_flag* flag, int default_target, int default_limit)
  72 {
  73   int ret = -1;
  74   size_t flaglen = strlen (flag->name);
  75   if (!env || !flag->name)
  76     return ret;
  77
  78
  79   do
  80     {
  81       if (!strncmp(env, flag->name, flaglen))
  82         {
  83           /* flagname matches */
  84           int limit;
  85           env += flaglen;
  86           if (*env == ':')
  87             for (limit = 0; limit<11; ++limit)
  88               {
  89                 size_t limitlen = strlen (nobug_limits[limit].name);
  90                 if (!strncmp(env, nobug_limits[limit].name, limitlen))
  91                   {
  92                     /* found :LIMIT */
  93                     int target;
  94                     env += limitlen;
  95                     if (*env == '@')
  96                       while (*env == '@')
  97                         {
  98                           for (target = 0; target<5; ++target)
  99                             {
 100                               size_t targetlen = strlen (nobug_targets[target]);
 101                               if (!strncmp(env, nobug_targets[target], targetlen))
 102                                 {
 103                                   /* @target found */
 104                                   env += targetlen;
 105                                   /* TODO target options are unimplemented
 106                                      switch (target)
 107                                      {
 108                                      case NOBUG_TARGET_RINGBUFFER:
 109                                      // filename flags size
 110                                      case NOBUG_TARGET_CONSOLE:
 111                                      //  FILE*
 112                                      case NOBUG_TARGET_FILE:
 113                                      // filename flags
 114                                      case NOBUG_TARGET_SYSLOG:
 115                                      // facility options prefix
 116                                      case NOBUG_TARGET_APPLICATION:
 117                                      }
 118                                   */
 119                                   ret = flag->limits[target] = nobug_limits[limit].value;
 120                                 }
 121                             }
 122                         }
 123                     else
 124                       {
 125                         /* flag:LIMIT with no @target */
 126                         ret = flag->limits[default_target] = nobug_limits[limit].value;
 127                       }
 128                   }
 129               }
 130           else
 131             {
 132               /* flag with no :LIMIT */
 133               ret = flag->limits[default_target] = default_limit;
 134             }
 135         }
 136       env = strchr(env, ',');
 137       if (env)
 138         ++env;
 139     }
 140   while (env);
 141   return ret;
 142 }
 143
 144
 145 int
 146 nobug_env_init_flag (struct nobug_flag* flag, int default_target, int default_limit)
 147 {
 148   nobug_init();
 149
 150   /* set some defaults */
 151   flag->ringbuffer_target = &nobug_default_ringbuffer;
 152   flag->console_target = stderr;
 153   flag->file_target = nobug_default_file;
 154
 155   /* parse $NOBUG_LOG */
 156   int ret = nobug_env_parse_flag (getenv("NOBUG_LOG"), flag, default_target, default_limit);
 157
 158   /* ensure that the ringbuffer is the most verbose */
 159   int i;
 160   int max;
 161
 162   for (i = NOBUG_TARGET_CONSOLE; i <= NOBUG_TARGET_APPLICATION; ++i)
 163     {
 164       max = max > flag->limits[i] ? max : flag->limits[i];
 165     }
 166
 167   flag->limits[NOBUG_TARGET_RINGBUFFER] = max > flag->limits[NOBUG_TARGET_RINGBUFFER]
 168     ? max : flag->limits[NOBUG_TARGET_RINGBUFFER];
 169   return ret;
 170 }