cfg_parser is a robust configuration file parser written in C++. It can read and write configuration files preserving any comments made inside the file. It supports escaped characters, quoted text and infinite line length (a whole line must fit into an STL string).

• keyword = value
• [Sections]
• # comments
• [Sections] # with comments
• keyword = value # pairs with comments
• keyword = „values with spaces, newlines \n, embedded quotes \“ and all other escape characters supported by printf„
• sloppy parsing: keyword= value is accepted as well as keyword=value or keyword value (withouth '=')
• displays parsing errors in a human friendly format (including filename, line number and line contents in question)

• cfg_parser-1.0.zip

#include <iostream>
#include <string>
 
#include "cfg_parser.h"
 
using namespace std;
 
int main(int argc, char *argv[]) {
    // First we need to initialize a new configuration
    ConfigParser cfg("test.cfg");
 
    // write everything into another config file
    cfg.writeFile("test2.cfg");
 
    // get value as integer of keyword 'hier' from the global section
    int i = cfg.getInt("hier");
    cout << "global hier=" << i << endl;
 
    // get value as integer of keyword 'hier' from section: mysection with default value = "" (which will be converted by atoi())
    i = cfg.getInt("hier", "", "mysection");
    cout << "section hier=" << i << endl;
 
   return 0;
}

Only relevant members are shown!

class ConfigParser {
public:
	ConfigParser(const std::string& in_file = "");
	~ConfigParser();
 
	// loads the given configuration file
	int readFile(const std::string& in_file);
	// writes the current configuration to the given file. I file not given, write back into the inputfile
	int writeFile(const std::string& out_file = "");
	// returns filname of loaded file
	void getFilename(std::string& in_file);
	// empty lines in config file are written back to the out_file if value = 1. (default = 0)
	void preserveEmptyLines(int value);
 
 
	// return variable from configuration (if non-existent, value remains unchanged)
	void getVar(const std::string& keyword, std::string& value, const std::string& section = "");
	// sets variable in configuration (section and/or variable are added if non-existent)
	void setVar(const std::string& keyword, const std::string& value, const std::string& section = "", const std::string& comment = "");
	// deletes variable from configuration
	void delVar(const std::string& keyword, const std::string& section = "");
 
	// returns integer if found, supplied default_value else
	int getInt(const std::string& keyword, const std::string& default_value = "", const std::string& section = "");
	// returns long if found, supplied default_value else
	long getLong(const std::string& option, const std::string& default_value = "", const std::string& section = "");
	// returns float if found, supplied default_value else
	float getFloat(const std::string& option, const std::string& default_value = "", const std::string& section = "");
	// returns double if found, supplied default_value else
	double getDouble(const std::string& option, const std::string& default_value = "", const std::string& section = "");
	// returns string if found, supplied default_value else
	std::string getString(const std::string& option, const std::string& default_value = "", const std::string& section = "");
 
 
	// adds a section to the configuration
	void addSection(const std::string& section, const std::string& comment = "");
	// deletes a section
	void delSection(const std::string& section);
 
	// displays current configuration content using cout
	void debug();
};

The following file is read-in correctly.

# Test file for cfg_parser

# lets begin with a comment.. well we already did :-)
# simple stuff
keyword = value
bla=123
test 234
text = "my loooong text including nested \" ! and line\nbreaks\n."

# little bit more complicated
   bal    =   asdfasdfas
	   text2="blaaaldflkadf"#evil comment
		  text3     =		"lets try a note
that lasts
for
more
than
a line"	# and including a comment :-)
# another comment

   
# yet another comment

adf = adfasdf #bla  a      dffff

[mysection]
hier = 1
hier = 2

[  a ]
adf adsf

[  asdf d]
a asdfdf