ConfigFile.h
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00001 // ConfigFile.h
00002 // Class for reading named values from configuration files
00003 // Richard J. Wagner  v2.1  24 May 2004  wagnerr@umich.edu
00004 
00005 // Copyright (c) 2004 Richard J. Wagner
00006 // 
00007 // Permission is hereby granted, free of charge, to any person obtaining a copy
00008 // of this software and associated documentation files (the "Software"), to
00009 // deal in the Software without restriction, including without limitation the
00010 // rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
00011 // sell copies of the Software, and to permit persons to whom the Software is
00012 // furnished to do so, subject to the following conditions:
00013 // 
00014 // The above copyright notice and this permission notice shall be included in
00015 // all copies or substantial portions of the Software.
00016 // 
00017 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
00018 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
00019 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
00020 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
00021 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
00022 // FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
00023 // IN THE SOFTWARE.
00024 
00025 // Typical usage
00026 // -------------
00027 // 
00028 // Given a configuration file "settings.inp":
00029 //   atoms  = 25
00030 //   length = 8.0  # nanometers
00031 //   name = Reece Surcher
00032 // 
00033 // Named values are read in various ways, with or without default values:
00034 //   ConfigFile config( "settings.inp" );
00035 //   int atoms = config.read<int>( "atoms" );
00036 //   double length = config.read( "length", 10.0 );
00037 //   string author, title;
00038 //   config.readInto( author, "name" );
00039 //   config.readInto( title, "title", string("Untitled") );
00040 // 
00041 // See file example.cpp for more examples.
00042 
00043 #ifndef CONFIGFILE_H
00044 #define CONFIGFILE_H
00045 
00046 #include <string>
00047 #include <map>
00048 #include <iostream>
00049 #include <fstream>
00050 #include <sstream>
00051 
00052 using std::string;
00053 
00054 class ConfigFile {
00055 // Data
00056 protected:
00057         string myDelimiter;  // separator between key and value
00058         string myComment;    // separator between value and comments
00059         string mySentry;     // optional string to signal end of file
00060         std::map<string,string> myContents;  // extracted keys and values
00061         
00062         typedef std::map<string,string>::iterator mapi;
00063         typedef std::map<string,string>::const_iterator mapci;
00064 
00065 // Methods
00066 public:
00067         ConfigFile( string filename,
00068                     string delimiter = "=",
00069                     string comment = "#",
00070                                 string sentry = "EndConfigFile" );
00071         ConfigFile();
00072         
00073         // Search for key and read value or optional default value
00074         template<class T> T read( const string& key ) const;  // call as read<T>
00075         template<class T> T read( const string& key, const T& value ) const;
00076         template<class T> bool readInto( T& var, const string& key ) const;
00077         template<class T>
00078         bool readInto( T& var, const string& key, const T& value ) const;
00079         
00080         // Modify keys and values
00081         template<class T> void add( string key, const T& value );
00082         void remove( const string& key );
00083         
00084         // Check whether key exists in configuration
00085         bool keyExists( const string& key ) const;
00086         
00087         // Check or change configuration syntax
00088         string getDelimiter() const { return myDelimiter; }
00089         string getComment() const { return myComment; }
00090         string getSentry() const { return mySentry; }
00091         string setDelimiter( const string& s )
00092                 { string old = myDelimiter;  myDelimiter = s;  return old; }  
00093         string setComment( const string& s )
00094                 { string old = myComment;  myComment = s;  return old; }
00095         
00096         // Write or read configuration
00097         friend std::ostream& operator<<( std::ostream& os, const ConfigFile& cf );
00098         friend std::istream& operator>>( std::istream& is, ConfigFile& cf );
00099         
00100 protected:
00101         template<class T> static string T_as_string( const T& t );
00102         template<class T> static T string_as_T( const string& s );
00103         static void trim( string& s );
00104 
00105 
00106 // Exception types
00107 public:
00108         struct file_not_found {
00109                 string filename;
00110                 file_not_found( const string& filename_ = string() )
00111                         : filename(filename_) {} };
00112         struct key_not_found {  // thrown only by T read(key) variant of read()
00113                 string key;
00114                 key_not_found( const string& key_ = string() )
00115                         : key(key_) {} };
00116 };
00117 
00118 
00119 /* static */
00120 template<class T>
00121 string ConfigFile::T_as_string( const T& t )
00122 {
00123         // Convert from a T to a string
00124         // Type T must support << operator
00125         std::ostringstream ost;
00126         ost << t;
00127         return ost.str();
00128 }
00129 
00130 
00131 /* static */
00132 template<class T>
00133 T ConfigFile::string_as_T( const string& s )
00134 {
00135         // Convert from a string to a T
00136         // Type T must support >> operator
00137         T t;
00138         std::istringstream ist(s);
00139         ist >> t;
00140         return t;
00141 }
00142 
00143 
00144 /* static */
00145 template<>
00146 inline string ConfigFile::string_as_T<string>( const string& s )
00147 {
00148         // Convert from a string to a string
00149         // In other words, do nothing
00150         return s;
00151 }
00152 
00153 
00154 /* static */
00155 template<>
00156 inline bool ConfigFile::string_as_T<bool>( const string& s )
00157 {
00158         // Convert from a string to a bool
00159         // Interpret "false", "F", "no", "n", "0" as false
00160         // Interpret "true", "T", "yes", "y", "1", "-1", or anything else as true
00161         bool b = true;
00162         string sup = s;
00163         for( string::iterator p = sup.begin(); p != sup.end(); ++p )
00164                 *p = toupper(*p);  // make string all caps
00165         if( sup==string("FALSE") || sup==string("F") ||
00166             sup==string("NO") || sup==string("N") ||
00167             sup==string("0") || sup==string("NONE") )
00168                 b = false;
00169         return b;
00170 }
00171 
00172 
00173 template<class T>
00174 T ConfigFile::read( const string& key ) const
00175 {
00176         // Read the value corresponding to key
00177         mapci p = myContents.find(key);
00178         if( p == myContents.end() ) throw key_not_found(key);
00179         return string_as_T<T>( p->second );
00180 }
00181 
00182 
00183 template<class T>
00184 T ConfigFile::read( const string& key, const T& value ) const
00185 {
00186         // Return the value corresponding to key or given default value
00187         // if key is not found
00188         mapci p = myContents.find(key);
00189         if( p == myContents.end() ) return value;
00190         return string_as_T<T>( p->second );
00191 }
00192 
00193 
00194 template<class T>
00195 bool ConfigFile::readInto( T& var, const string& key ) const
00196 {
00197         // Get the value corresponding to key and store in var
00198         // Return true if key is found
00199         // Otherwise leave var untouched
00200         mapci p = myContents.find(key);
00201         bool found = ( p != myContents.end() );
00202         if( found ) var = string_as_T<T>( p->second );
00203         return found;
00204 }
00205 
00206 
00207 template<class T>
00208 bool ConfigFile::readInto( T& var, const string& key, const T& value ) const
00209 {
00210         // Get the value corresponding to key and store in var
00211         // Return true if key is found
00212         // Otherwise set var to given default
00213         mapci p = myContents.find(key);
00214         bool found = ( p != myContents.end() );
00215         if( found )
00216                 var = string_as_T<T>( p->second );
00217         else
00218                 var = value;
00219         return found;
00220 }
00221 
00222 
00223 template<class T>
00224 void ConfigFile::add( string key, const T& value )
00225 {
00226         // Add a key with given value
00227         string v = T_as_string( value );
00228         trim(key);
00229         trim(v);
00230         myContents[key] = v;
00231         return;
00232 }
00233 
00234 #endif  // CONFIGFILE_H
00235 
00236 // Release notes:
00237 // v1.0  21 May 1999
00238 //   + First release
00239 //   + Template read() access only through non-member readConfigFile()
00240 //   + ConfigurationFileBool is only built-in helper class
00241 // 
00242 // v2.0  3 May 2002
00243 //   + Shortened name from ConfigurationFile to ConfigFile
00244 //   + Implemented template member functions
00245 //   + Changed default comment separator from % to #
00246 //   + Enabled reading of multiple-line values
00247 // 
00248 // v2.1  24 May 2004
00249 //   + Made template specializations inline to avoid compiler-dependent linkage
00250 //   + Allowed comments within multiple-line values
00251 //   + Enabled blank line termination for multiple-line values
00252 //   + Added optional sentry to detect end of configuration file
00253 //   + Rewrote messy trimWhitespace() function as elegant trim()


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Author(s): Jason Derenick , Thomas Miller
autogenerated on Sun May 5 2019 02:28:23