ConfigFile.cpp

00001 /*
00002  * ConfigFile.cpp
00003  * Simple Config file reader class
00004  *
00005  * Copyright (c) 2011 Peter Brier
00006  *
00007  *   This file is part of the LaOS project (see: http://wiki.protospace.nl/index.php/LaOS)
00008  *
00009  *   LaOS is free software: you can redistribute it and/or modify
00010  *   it under the terms of the GNU General Public License as published by
00011  *   the Free Software Foundation, either version 3 of the License, or
00012  *   (at your option) any later version.
00013  *
00014  *   LaOS is distributed in the hope that it will be useful,
00015  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
00016  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00017  *   GNU General Public License for more details.
00018  *
00019  *   You should have received a copy of the GNU General Public License
00020  *   along with LaOS.  If not, see <http://www.gnu.org/licenses/>.
00021  * 
00022  */
00023 #include "ConfigFile.h"
00024 
00025 // Make new config file object
00026 ConfigFile::ConfigFile(char *file) 
00027 {
00028   printf("ConfigFile:ConfigFile (%s)\n\r", file);
00029   extern LaosFileSystem sd;
00030   printf("ConfigFile(%s)\n\r", file);
00031   fp =sd.openfile(file, "rb");
00032   if (fp==NULL) {
00033     printf("Local configfile\n\r");
00034     char tmpname[32];
00035     sprintf(tmpname, "/local/%s", file);
00036     printf("name: %s\n\r", tmpname); 
00037     fp = fopen(tmpname,"rb");
00038   }
00039 }
00040 
00041 // Destroy a config file (closes the file handle)
00042 ConfigFile::~ConfigFile() 
00043 {
00044    printf("~ConfigFile()\n\r");
00045   if ( fp != NULL )
00046     fclose(fp);
00047 }
00048 
00049 // Read value
00050 bool ConfigFile::Value(char *key, char *value,  size_t maxlen, char *def)
00051 {
00052   int m=0,n=0,c,s=0;
00053   char *v = value;
00054   if (fp == NULL)
00055   {
00056     strncpy(value, def, maxlen);
00057     return false;
00058   }
00059 
00060   n = strlen(key);
00061   fseek(fp, 0L, SEEK_SET);
00062   while( s != 99  ) 
00063   {
00064     c = fgetc(fp);
00065     if ( c == EOF ) 
00066       break;
00067   //  printf("%d(%d): '%c'\n\r", s, m, c);
00068     switch( s  )// sate machine
00069     { 
00070       case 0: // (re) start: note: no break; fall through to case 1
00071         m=0; 
00072         s=1;
00073       case 1: // read key, skip spaces
00074         if ( c == key[m] ) 
00075           m++; 
00076         else 
00077           s = 0;
00078         if ( c == ';' ) 
00079           s = 10; 
00080         else if ( c == ' ' || c == '\t' || c == '\n' || c == '\r') 
00081         {
00082           if ( n == m ) // key found
00083           {
00084             s = 2;
00085             m = 0; 
00086           }
00087           else
00088             s = 0;
00089         }
00090         break;
00091       case 2: // key matched, skip whitepaces upto the first char
00092         if ( c == ';' ) s = 99;
00093         else if ( c != ' ' && c != '\t' ) 
00094         { 
00095           s = 3;
00096           m = 1;
00097           if ( m < maxlen) 
00098             *value++ = c;
00099         }
00100         break;
00101         
00102       case 3: // copy value content, upto eol or comment
00103         if ( m == maxlen || c == '\n' || c == '\r' || c == ';' ) 
00104           s = 99;
00105         else
00106         {
00107           m++;
00108           *value++ = c;
00109         }
00110         break;         
00111       case 10: // skip comments, upto eol or eof
00112         if ( c == '\n' || c == '\r' ) s = 0;
00113         break;
00114      }
00115   }
00116   if ( s == 99 && m > 0) // key found, and value assigned
00117   {
00118     *value = 0; // terminate string
00119     printf("'%s'='%s'\n", key,v);
00120     return true; 
00121   }
00122   else
00123   {
00124     strncpy(value, def, maxlen);
00125     printf("'%s'='%s' (default)\n", key,v);
00126     return false;
00127   } 
00128 }
00129 
00130 
00131 // Read int value
00132 bool ConfigFile::Value(char *key, int *value, int def)
00133 {
00134   char val[32];
00135   bool b = Value(key, val, 31, "");
00136   if ( b )
00137   {
00138     *value = atoi(val);
00139      printf("%s: numeric value=%d\n", key, *value);
00140   }
00141   else
00142   {
00143     *value = def;
00144      printf("%s default (%d)\n", key, *value);
00145   }
00146   return b;
00147 }