How to Read and Write an INI File

Environment: Visual C++ 6, Win32, MFC, Win XP, Win 2000


CIniReader is a class that reads and writes to and from an INI file. Here is a functions list of this class:

Function Description
setINIFileName Sets the INI File name to read and write.
getKeyValue Retrieves a key value given the section and key name.
getSectionData Retrieves all key/value pairs of a given section.
getSectionNames Retrieves all the sections in an INI file.
sectionExists Finds out whether a given section exists.
setKey Modifies the key value or to create a key value pair for the specified section.

The functions in CIniReader use GetPrivateProfilexxx () functions to set and get information stored in an INI file. By having idea of the SDK functions such as GetPrivateProfilexxx (), the functionality of the class can easily be extended.

Here is the CIniReader header file:

// CIniReader- Header File

class CIniReader
// method to set INI file name, if not already specified
void setINIFileName(CString strINIFile);

// methods to return the lists of section data and section names
CStringList* getSectionData(CString strSection);
CStringList* getSectionNames();

// check whether the section exists in the file
BOOL sectionExists(CString strSection);

// updates the key value, if key already exists,
// else creates a key-value

long setKey(CString strValue, CString strKey,
CString strSection);

// give the key value for the specified key of a section
CString getKeyValue(CString strKey,CString strSection);

// default constructor
m_sectionList = new CStringList();
m_sectionDataList = new CStringList();

CIniReader(CString strFile)
m_strFileName = strFile;
m_sectionList = new CStringList();
m_sectionDataList = new CStringList();

delete m_sectionList;
delete m_sectionDataList;

// lists to keep sections and section data
CStringList *m_sectionDataList;
CStringList *m_sectionList;

CString m_strSection;
long m_lRetValue;

// ini file name
CString m_strFileName;

How to Use the Class

The demo project shows how to use the class. It takes from the user the fully qualified path and name of the INI file as “C:\WINDOWS\ODBC.INI” in the INI File name edit box. List Sections fills the list of sections in the INI file. Specifying any of the section names and clicking the List Keys buttons will fill the second list box with the section data (all key and value pairs). Specifying a key name and pressing the Show Key Value button will display the value of the key. Update Key Value will update the modified value from the key value edit box for the key. If the key is not already present, the update key value will create the specified key-value pair in the INI file. Be sure about what you are doing because it will modify the keys and values of the INI file.

Currently, the buffer limit is up to 2000 characters; this can be increased according to the requirement.

After setting the INI file name just as the following code shows, you can proceed with CIniReader functions:

// example of using the setINIFileName method
CIniReader m_IniReader;
m_IniReader.setINIFileName (m_strINIFile);

That’s it. The class is so simple and easy to use, I am sure you will have no problem.

About the Author

Aisha has an M.Sc. in Computer Science with a top position in her university. She has worked mainly in VC++ 6, MFC, ATL, COM/DCOM, ActiveX, C++, ASP, VB, SQL, and so forth. These days, she is working on the dot-Net framework, managed C++, and C#. Inspired with nature, she loves to seek knowledge. She is so fond of travelling that she don’t want to die without seeing this whole world.

E-mail: [email protected]

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Download demo project – 2 Kb

Download source project – 33 Kb

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