ConfigFile

Overview

Some applications need variable configurations.

For example, The configuration of account information for Twitter...

It's not good for publish if I implemented a program with a account information for Twitter, and it's not secure.

So, in this document we will show you a configuration file helper class for local file system on mbed.

You can use a variable configuration with it.

Basic concept

A configuration set consist from a key and a value.

How to use it?

Configuration file

We need a configuration file.

A comment line started by #.
Empty lines have not meaning.
Key=Value based configuration.
A space character in a side of a key and a value have a meaning.

Configurtion file example

#
# Configuration file for mbed.
#

MyKey1=This is a value for key1.
MyKey2=Value 2

Message1 = This is a test message no.1
 Message2  =  This is a test message no.2
  Message3   =   This is a test message no.3

Reading

This example codes read a file named input.cfg on mbed local file system.

Code

#include "mbed.h"
#include "ConfigFile.h"
 
LocalFileSystem local("local");
ConfigFile cfg;

int main(void) {
    char *key = "MyKey";
    char value[BUFSIZ];
    /*
     * Read a configuration file from a mbed.
     */
    if (!cfg.read("/local/input.cfg")) {
        error("Failure to read a configuration file.\n");
    }

    /*
     * Get a configuration value.
     */
    if (cfg.getValue(key, &value[0], sizeof(value))) {
        printf("'%s'='%s'\n", key, value);
    }
}

Ignore comments in a configuration file.
Ignore empty lines in a configuration file.
Keep spaces in side of keys and values.

Writing

This example codes write a configuration to a file.

Code

#include "mbed.h"
#include "ConfigFile.h"
 
LocalFileSystem local("local");
ConfigFile cfg;

int main(void) {

    /*
     * Set a configuration value.
     */
    if (!cfg.setValue("MyKey", "TestValue")) {
        error("Failure to set a value.\n");
    }    

    /*
     * Write to a file.
     */
    if (!cfg.write("/local/output.cfg")) {
        error("Failure to write a configuration file.\n");
    }
}

Library API

» Import this library into a program
ConfigFile - ConfigFile Class Reference

Public Member Functions
	ConfigFile ()
	Create a configuration file class.
	~ConfigFile ()
	Destroy a configuration file class.
bool	getValue (char key, char value, size_t siz)
	Get a value for a key.
bool	setValue (char key, char value)
	Set a set of a key and value.
bool	remove (char *key)
	Remove a config.
bool	removeAll (void)
	Remove all config.
int	getCount ()
	Get a number of configuration sets.
bool	getKeyAndValue (int index, char key, size_t keybufsiz, char value, size_t valuebufsiz)
	Get a key and a value.
bool	read (char *file)
	Read from the target file.
bool	write (char file, char header=NULL, FileFormat ff=UNIX)
	Write from the target file.

ConfigFile

Overview

Basic concept

How to use it?

Configuration file

Configurtion file example

Reading

Code

Writing

Code

Library API

» Import this library into a program
ConfigFile - ConfigFile Class Reference

Public Member Functions

Example application

» Import this program ConfigFile_TestProgram

References

ConfigFile

Overview

Basic concept

How to use it?

Configuration file

Configurtion file example

Reading

Code

Writing

Code

Library API

» Import this library into a programConfigFile - ConfigFile Class Reference

Public Member Functions

Example application

» Import this programConfigFile_TestProgram

References

» Import this library into a program
ConfigFile - ConfigFile Class Reference

» Import this program ConfigFile_TestProgram