Save configuration using file.hpp

mrw/configfile.cpp

@@ -9,6 +9,9 @@
     @license LGPL, see file <a href="license.html">COPYING</a>
 
     $Log$
+    Revision 1.2  2005/01/28 07:49:32  marc
+    Save configuration using file.hpp
+
     Revision 1.1  2005/01/07 00:31:38  marc
     initial version
 
@@ -20,6 +23,7 @@
 #include <mrw/configfile.hpp>
 #include <mrw/exception.hpp>
 #include <mrw/string.hpp>
+#include <mrw/file.hpp>
 #include <fstream>
 
 mrw::ConfigFileReader::Value&
@@ -38,26 +42,9 @@ mrw::ConfigFileReader& mrw::ConfigFileReader::load(const std::string& filename)
 }
 
 mrw::ConfigFileReader& mrw::ConfigFileReader::reload() throw(std::exception) {
-  return parse(readFile());
+  return parse(mrw::File::read(_filename));
-}
-
-std::string mrw::ConfigFileReader::readFile() const throw(std::exception) {
-  std::string fileContents; // declaration as first allows optimization
-  std::ifstream file(_filename.c_str());
-  if (!file)
-    throw mrw::invalid_argument("Error file not found: '"+_filename+"'");
-  file.seekg(0, std::ios::end);
-  int size(file.tellg());
-  fileContents.resize(size); // make buffer long enough to store all
-  file.seekg(0, std::ios::beg);
-  file.read(fileContents.begin().operator->(), size); // hack to get the buffer
-  if (!file.good() && file.eof())
-    throw mrw::invalid_argument("Error reading file: '"+_filename+"'");  
-  return fileContents;
 }
 
-#include <iostream>
-using namespace std;
 mrw::ConfigFileReader& mrw::ConfigFileReader::parse(const std::string& file)
   throw(std::exception) {
   _values.erase(_values.begin(), _values.end());
@@ -142,7 +129,7 @@ mrw::ConfigFileReader&
 mrw::ConfigFileWriter&
 #endif
 mrw::ConfigFileWriter::reload() throw(std::exception) {
-  return parse(_file=readFile());
+  return parse(_file=mrw::File::read(_filename));
 }
 
 mrw::ConfigFileWriter& mrw::ConfigFileWriter::save() throw(std::exception) {
@@ -193,10 +180,6 @@ mrw::ConfigFileWriter& mrw::ConfigFileWriter::save() throw(std::exception) {
           _sections[sec->first] = _file.size();
         }
       }
-  if (!changed) return *this;
+  if (changed) mrw::File::save(_filename, _file);
-  // save to file
-  std::ofstream file(_filename.c_str());
-  if (!(file<<_file))
-    throw mrw::invalid_argument("Cannot write file '"+_filename+"'");
   return *this;
 }

mrw/configfile.hpp

@@ -9,6 +9,9 @@
     @license LGPL, see file <a href="license.html">COPYING</a>
 
     $Log$
+    Revision 1.2  2005/01/28 07:49:32  marc
+    Save configuration using file.hpp
+
     Revision 1.1  2005/01/07 00:31:38  marc
     initial version
 
@@ -24,6 +27,8 @@ namespace mrw {
 
   /** @defgroup config Configuration File Handler
 
+      @pre #include <mrw/configfile.hpp>
+
       Read configuration parameters from a file.
 
       @section configSyntax Configuration File Syntax
@@ -162,178 +167,268 @@ namespace mrw {
       */
   //@{
 
-  /// Parse configuration file and access the contents.
+  //============================================================================
-  /** Parse a configuration file that consists of sections containing
+  /** @brief Parse configuration file and access the contents.
+      
+      Parse a configuration file that consists of sections containing
       variables with values. This class does not store anything in the
       file, even if variables have changed.
-      @see If you want %to save changes %to the file, use
+      
-           @ref ConfigFileWriter.
+      @see If you want %to save changes %to the file, use @ref ConfigFileWriter.
-      @see For details, see @ref configSyntax. */
+      @see For details, see @ref configSyntax.
+      */
   class ConfigFileReader {
+
+      //............................................................... typedefs
     public:
+
+      //------------------------------------------------------------------ Value
       /// A configuration file value.
       class Value {
+
+          //............................................................ methods
         public:
-      /// Get the value string.
+      
-      /** Get the value string. Trailing and leading white spaces have
+          /** @brief Get the value string.
+          
+              Get the value string. Trailing and leading white spaces have
               been truncated. If the variable was quoted, quotes have been
               removed.
-          @return the variable's value as string */
+          
+              @return the variable's value as string
+              */
           operator const std::string&() const throw() {
             return value;
           }
-      /// Get the value string.
+      
-      /** Alternative access to the variable's contents. Trailing and
+          /** @brief Get the value string.
+          
+              Alternative access to the variable's contents. Trailing and
               leading white spaces have been truncated. If the variable
               was quoted, quotes have been removed.
-          @return the variable's value as string */
+
+              @return the variable's value as string
+              */
           const std::string& operator()() const throw() {
             return value;
           }
-      /// Assign a new value.
+      
-      /** Assign a new value. The new value is lost if you use the
+          /** @brief Assign a new value.
+
+              Assign a new value. The new value is lost if you use the
               ConfigFileReader, but it is stored in the destructor, if you
-          use the ConfigFileWriter instead. */
+              use the ConfigFileWriter instead.
+              */
           Value& operator=(const std::string& newValue) throw() {
             changed = true;
             value = newValue;
             return *this;
           }
+      
           /// Compare the value to a string.
           bool operator==(const std::string& o) const throw() {
             return o==value;
           }
+      
           /// Compare a string to the value.
           friend bool operator==(const std::string& o, const Value& v) throw() {
             return v==o;
           }
+          
+          //............................................................ methods
         protected:
+      
           friend class ConfigFileReader;
           friend class ConfigFileWriter;
-      Value(const std::string& v,
+      
-            std::string::size_type s, std::string::size_type e) throw():
+          Value(const std::string& v, std::string::size_type s,
-        value(v), changed(false), start(s), end(e) {
+                std::string::size_type e) throw():
-      }
+            value(v), changed(false), start(s), end(e) {}
+          
           Value(const std::string& v) throw():
             value(v), changed(true), start(0), end(0) {
           }
+
+          //.......................................................... variables
+        protected:
+          
           std::string value;
           bool changed;
           std::string::size_type start;
           std::string::size_type end;
+
+          //............................................................ methods
         private:
+      
           Value(); // not implemented, must be initialized
           Value& operator=(const Value&); // not implemented, no assignment
+      
       };
-    /// Uninitialized construction.
+      //------------------------------------------------------------------------
-    /** Uninitialized construction. Use this constructor, if you want
+
-        to call @ref load() later. */
+      //................................................................ methods
+    public:
+      
+      /** @brief Uninitialized construction.
+          
+          Uninitialized construction. Use this constructor, if you
+          want to call @ref load() later.
+          */
       ConfigFileReader() throw() {}
-    /// Parse a file at construction.
+      
-    /** This should be the normal case: load and parse the file at
+      /** @brief Parse a file at construction.
+
+          This should be the normal case: load and parse the file at
           construction.
+
           @param filename the name of the file to read
           @throw mrw::invalid_argument
                   - if the file does not exist
                   - if reading the file fails
                   - if there is an unterminated section name in the file
-                - if there is an empty variable name in the file */
+                  - if there is an empty variable name in the file
+          */
       ConfigFileReader(const std::string& filename) throw(std::exception):
         _filename(filename) {
         reload();
       }
+      
       /// Copy construct from other ConfigFileReader.
       ConfigFileReader(const ConfigFileReader& o) throw():
           _filename(o._filename), _values(o._values) {
       }
+      
       virtual ~ConfigFileReader() throw() {}
+      
       /// Copy from other ConfigFileReader.
       ConfigFileReader& operator=(const ConfigFileReader& o) {
         _filename = o._filename;
         _values = o._values;
         return *this;
       }
-    /// Access a value read from the file.
+      
-    /** Access a value read from the file.
+      /** @brief Access a value read from the file.
+
+          Access a value read from the file.
+
           @param section the section in the configuration file
           @param name the variable name
           @param default_ the default value that is set, if the variable is
                           not configured
-        @return the Value you are looking for */
+          @return the Value you are looking for
+          */
       Value& operator()(const std::string& section, const std::string& name,
                         const std::string& default_)
         throw(std::bad_exception);
-    /// Load and parse a new file.
+      
-    /** Load and parse a new file.
+      /** @brief Load and parse a new file.
+
+          Load and parse a new file.
+
+          @param filename the name of the file to load
           @throw mrw::invalid_argument
                   - if the file does not exist
                   - if reading the file fails
                   - if there is an unterminated section name in the file
-                - if there is an empty variable name in the file */
+                  - if there is an empty variable name in the file
+          */
       ConfigFileReader& load(const std::string& filename) throw(std::exception);
-    /// Reload the last file again.
+      
-    /** Reload the last file again.
+      /** @brief Reload the last file again.
+
+          Reload the last file again.
+
           @throw mrw::invalid_argument
                   - if the file does not exist
                   - if reading the file fails
                   - if there is an unterminated section name in the file
-                - if there is an empty variable name in the file */
+                  - if there is an empty variable name in the file
+          */
       virtual ConfigFileReader& reload() throw(std::exception);
+
+      //............................................................... typedefs
     protected:
+      
       typedef std::map< std::string, std::map<std::string, Value> > Values;
       typedef std::map<std::string, std::string::size_type> Sections;
-    std::string readFile() const throw(std::exception);
+
+      //.............................................................. variables
+    protected:
+      
+      std::string _filename;
+      Values _values;
+      Sections _sections;
+
+      //................................................................ methods
+    protected:
+
       ConfigFileReader& parse(const std::string& file) throw(std::exception);
+      
       std::string parseSection(const std::string& file,
                                std::string::size_type& pos)
         const throw(std::exception);
+      
       Values::mapped_type::value_type parseValue(const std::string& file,
                                                  std::string::size_type& pos)
         const throw(std::exception);
+      
       std::string parseComment(const std::string& file,
                                std::string::size_type& pos)
         const throw(std::bad_exception);
-    std::string _filename;
-    Values _values;
-    Sections _sections;
   };
 
+  //============================================================================
   /** @brief Parse configuration file and offer read&nbsp;/ write
              access to the contents.
       
       Parse a configuration file that consists of sections containing
       variables with values. This class stores the file in the destructor
       if variables have changed.
-      @see If you want %to leave the file untouched, use
+      
-           @ref ConfigFileReader.
+      @see If you want %to leave the file untouched, use @ref ConfigFileReader.
-      @see For details, see @ref configSyntax. */
+      @see For details, see @ref configSyntax.
+      */
   class ConfigFileWriter: virtual public ConfigFileReader {
+
+      //................................................................ methods
     public:
-    /// Uninitialized construction.
+      
-    /** @copydoc ConfigFileReader() */
+      /** @brief Uninitialized construction.
+
+          @copydoc ConfigFileReader()
+          */
       ConfigFileWriter() throw() {}
-    /// Parse a file at construction.
+      
-    /** @copydoc ConfigFileReader(const std::string& filename) */
+      /** @brief Parse a file at construction.
+
+          @copydoc ConfigFileReader(const std::string&)
+          */
       ConfigFileWriter(const std::string& filename) throw(std::exception) {
         load(filename);
       }
+      
       /// Copy construct from other ConfigFileWriter.
       ConfigFileWriter(const ConfigFileWriter& o) throw():
         ConfigFileReader(o) {
       }
+      
       /// The file is stored at destruction.
       virtual ~ConfigFileWriter() throw() {
         save();
       }
+      
       /// Copy from other ConfigFileWriter.
       ConfigFileWriter& operator=(const ConfigFileWriter& o) {
         ConfigFileReader::operator=(o);
         return *this;
       }
+      
       // GNU g++ prior to 3.4 does not implement covariant returns
 #     if __GNUC__ == 3 && __GNUC_MINOR__ < 4
-    /// Reload the last file again.
+      /** @brief Reload the last file again.
-    /** @copydoc mrw::ConfigFileReader::reload()
+
+          @copydoc mrw::ConfigFileReader::reload()
+
           @bug Bug in GNU g++ compiler:
                return type should be <code>ConfigFileWriter&</code>,
                but the compiler sais:<br>
@@ -342,19 +437,29 @@ namespace mrw {
                covariant returns</code><br>
                The problem is fixed since GNU g++ 3.4, so the signature
                will be changed as soon as you upgrade to the new compiler
-             version. */
+               version.
+          */
       virtual ConfigFileReader& reload() throw(std::exception);
 #     else
-    /// Reload the last file again.
+      /** @brief Reload the last file again.
-    /** @copydoc mrw::ConfigFileReader::reload() */
+
+          @copydoc mrw::ConfigFileReader::reload()
+          */
       virtual ConfigFileWriter& reload() throw(std::exception);
 #     endif
-    /// Saves changes back to the file.
+      
-    /** All changed parameters are stored in the configuration
+      /** @brief Saves changes back to the file.
-        file. The rest of the file is left untouched. */
+
+          All changed parameters are stored in the configuration
+          file. The rest of the file is left untouched.
+          */
       ConfigFileWriter& save() throw(std::exception);
+
+      //.............................................................. variables
     protected:
+      
       std::string _file;
+      
   };
   
   //@}

mrw/file.hpp

@@ -1,3 +1,4 @@
+
 /** @file
 
     $Id$
@@ -9,6 +10,9 @@
     @license LGPL, see file <a href="license.html">COPYING</a>
 
     $Log$
+    Revision 1.2  2005/01/28 07:49:32  marc
+    Save configuration using file.hpp
+
     Revision 1.1  2005/01/07 00:31:38  marc
     initial version
 
@@ -22,26 +26,289 @@
 #include <mrw/exception.hpp>
 #include <string>
 #include <fstream>
+#include <sys/types.h>
+#include <dirent.h>
 
 namespace mrw {
+
+  /** @defgroup sysFile File and System Utilities
+
+      @brief By now, some utilies for file handling, i.e. a copy command.
+
+      Some file and system specific utilities are missing in C++ and
+      often there is even no good alternative in C libraries.
+      */
+  //@{
+
+  //============================================================================
+  /** @brief File handling utilities.
+
+      Utilities for file access in C++.
+      */
   class File {
+
+      //................................................................ methods
     public:
-    static void copy(std::string from, std::string to) throw (std::exception) {
+    
-      std::ifstream is(from.c_str());
+      /** @brief Copy a file.
-      if (!is)
+
-        throw mrw::invalid_argument("Cannot read file: '"+from+"'");
+          Copy a file to a new location.
-      is.seekg(0, std::ios::end);
+        
-      int size(is.tellg());
+          First the source file is fully read into memory, then written
-      std::string contents(size, 0); // make buffer long enough to store all
+          to the destination. If the source file cannot be fully read,
-      is.seekg(0, std::ios::beg);
+          the destination is left untouched.
-      is.read(contents.begin().operator->(), size); // hack to get the buffer
+
-      if (!is.good() && is.eof())
+          @throw mrw::invalid_argument if read or write fails
-        throw mrw::invalid_argument("Cannot read file: '"+from+"'");
+          @param from the source file name
+          @param to the destination file name
+          @note If the destination file already exists, it will be overwritten.
+          */
+      static void copy(const std::string& from,
+                       const std::string& to) throw(std::exception) {
         std::ofstream os(to.c_str());
-      os<<contents;
+        os<<read(from);
         if (!os) throw mrw::invalid_argument("Cannot write file: '"+to+"'");
       }
+    
+      /** @brief Read a file fully into memory.
+
+          Read a file fully into memory.
+        
+          @throw mrw::invalid_argument if read fails
+          @param filename the file to read
+          @return the file's contents
+          */
+      static std::string read(const std::string& filename)
+              throw(std::exception) {
+        std::string contents; // declare on top to allow compiler optimization
+        std::ifstream is(filename.c_str());
+        std::string::size_type sz(size(is, filename));
+        contents.resize(sz); // make buffer long enough to store all
+        is.read(contents.begin().operator->(), sz); // hack to get the buffer
+        if (!is.good() && is.eof())
+          throw mrw::invalid_argument("Cannot read file: '"+filename+"'");
+        return contents;
+      };
+    
+      /** @brief Save a string to a file.
+
+          A string is stored in a file, the whole file is overwritten by
+          the contents of the string. This is the counterpart of
+          read(const std::string&).
+
+          @throw mrw::invalid_argument if write fails
+          @param filename the name of the output file
+          @param contents the text to be written to the file
+          */
+      static void save(const std::string& filename, const std::string& contents)
+              throw(std::exception) {
+        std::ofstream file(filename.c_str());
+        if (!(file<<contents))
+          throw mrw::invalid_argument("Cannot write file '"+filename+"'");
+      }
+    
+      /** @brief Get the size of a file
+
+          Get the size of a file.
+        
+          @throw mrw::invalid_argument if read fails
+          @param filename the file name
+          @return the file's size
+          */
+      static std::string::size_type size(const std::string& filename)
+              throw(std::exception) {
+        std::ifstream is(filename.c_str());
+        if (!is)
+          throw mrw::invalid_argument("Cannot get size of file: '"
+                                      +filename+"'");
+        is.seekg(0, std::ios::end);
+        if (!is)
+          throw mrw::invalid_argument("Cannot get size of file: '"
+                                      +filename+"'");
+        return is.tellg();
+      }
+    
+      /** @brief Get the size of a file
+
+          Get the size of a file.
+        
+          @throw mrw::invalid_argument if read fails
+          @param file the filestream
+          @param filename the name of the file (required for the exception)
+          @return the file's size
+          */
+      static std::string::size_type size(std::ifstream& file,
+                                         const std::string& filename = "")
+              throw(std::exception) {
+        if (!file)
+          throw mrw::invalid_argument("Cannot get size of file: '"
+                                      +filename+"'");
+        file.seekg(0, std::ios::end);
+        std::string::size_type sz(file.tellg());
+        file.seekg(0, std::ios::beg);
+        if (!file)
+          throw mrw::invalid_argument("Cannot get size of file: '"
+                                      +filename+"'");
+        return sz;
+      }
+  };
+
+  //============================================================================
+  class Dir {
+
+      //............................................................... typedefs
+    public:
+      
+      //------------------------------------------------------------------ Entry
+      class Entry {
+
+          //........................................................... typedefs
+        public:
+
+          /** @brief The type of the actual file.
+
+              The type of the actual file.
+              
+              @note On some systems UNKNOWN is the only
+                    value returned.
+              */
+          enum FileType {
+            UNKNOWN = DT_UNKNOWN, ///< The type is unknown.
+            REGULAR = DT_REG,     ///< A regular file.
+            DIR     = DT_DIR,     ///< A directory.
+            FIFO    = DT_FIFO,    ///< A named pipe, or FIFO.
+            SOCKET  = DT_SOCK,    ///< A local-domain socket.
+            CHAR    = DT_CHR,     ///< A character device.
+            BLOCK   = DT_BLK      ///< A block device.
+          };
+
+          //............................................................ methods
+        public:
+
+          Entry(): _new(true) {}
+
+          /// Get the name of the actual file.
+          operator const std::string&() throw(std::bad_exception) {
+            if (_new) { // only convert to string once
+              _new = false;
+              _name = _dirent.d.d_name;
+            }
+            return _name;
+          }
+
+          /// Get the name of the actual file.
+          const std::string& operator()() throw(std::bad_exception) {
+            return *this;
+          }
+
+          /// Get the type of the actual file.
+          operator FileType() const throw() {
+            return FileType(_dirent.d.d_type);
+          }
+
+          //.......................................................... variables
+        private:
+
+          friend class Dir;
+
+          union { // for portability reasons, see "info readdir_r"
+              dirent d;
+              char b[offsetof (struct dirent, d_name) + NAME_MAX + 1];
+          } _dirent;
+
+          bool _new;
+          std::string _name;
+
+          //............................................................ methods
+        private:
+
+          dirent& entry() throw() {
+            _new = true;
+            return _dirent.d;
+          }
+      };
+      //------------------------------------------------------------------------
+
+      //................................................................ methods
+    public:
+
+      /** @brief Open a directory for reading the file list.
+
+          Open a directory for reading the file list.
+
+          @throw mrw::invalid_argument if directory cannot be opened
+          @param dir name of the directory to open
+          @param ignoreDots ignore directories <code>.<code> and
+                            <code>..</code> (self anf top)
+          */
+      Dir(const std::string& dir, bool ignoreDots=true) throw(std::exception):
+          _ignoreDots(ignoreDots), _dir(opendir(dir.c_str())) {
+        if (!_dir)
+          throw mrw::invalid_argument("Cannot read directory: '"+dir+'\'');
+      }
+
+      /// Directory is closed automatically in the destructor.
+      ~Dir() throw() {
+        closedir(_dir);
+      }
+
+      /** @brief Advance to the next directory entry.
+
+          Advance to the next directory entry.
+
+          @code
+          mrw::Dir dir("/home");
+          while (dir) ...
+          @endcode
+
+          @return
+            - @c true if an entry has been found
+            - @c false if there are no more entries left
+
+          @warning If you call this method again after @c false was
+                   returned, behaviour is unspecified, but a crash
+                   is probable.
+          */
+      operator bool() throw() {
+        static const std::string D("."), DD("..");
+        static dirent* fake;
+        if (readdir_r(_dir, &_entry.entry(), &fake)) return false;
+        if (_ignoreDots && _entry==Entry::DIR && (D==_entry() || D==_entry()))
+          return operator bool();
+        return true;
+      }
+
+      /** @brief Get the actual directory entry.
+
+          Returns the actual directory entry.
+
+          @code
+          mrw::Dir dir("/home");
+          while (dir) {
+            dirent entry(dir());
+            ...
+          }
+          @endcode
+
+          @return the actual directory entry
+
+          @warning You must first call operator bool(), otherwise the
+                   behaviour is undefined, but a crash is probable.
+          */
+      const Entry& operator()() {
+        return _entry;
+      }
+
+      //.............................................................. variables
+    private:
+
+      bool _ignoreDots;
+      DIR* _dir;
+      Entry _entry;
+      
   };
+  
+  //@}
 }
 
 #endif