The GetPrivateProfileString function retrieves a string from the specified section in an initialization file. This function is provided for compatibility with 16-bit Windows-based applications. Win32-based applications should store initialization information in the registry.
DWORD GetPrivateProfileString(
LPCTSTR lpAppName, // points to section name
LPCTSTR lpKeyName, // points to key name
LPCTSTR lpDefault, // points to default string
LPTSTR lpReturnedString, // points to destination buffer
DWORD nSize, // size of destination buffer
LPCTSTR lpFileName // points to initialization filename
);
Avoid specifying a default string with trailing blank characters. The function inserts a null character in the lpReturnedString buffer to strip any trailing blanks.
Windows 95: Although lpDefault is declared as a constant parameter, the system strips any trailing blanks by inserting a null character into the lpDefault string before copying it to the lpReturnedString buffer.
Windows NT: The system does not modify the lpDefault string. This means that if the default string contains trailing blanks, the lpReturnedString and lpDefault strings will not match when compared using the lstrcmp function.
The return value is the number of characters copied to the buffer, not including the terminating null character.
If neither lpAppName nor lpKeyName is NULL and the supplied destination buffer is too small to hold the requested string, the string is truncated and followed by a null character, and the return value is equal to nSize minus one.
If either lpAppName or lpKeyName is NULL and the supplied destination buffer is too small to hold all the strings, the last string is truncated and followed by two null characters. In this case, the return value is equal to nSize minus two.
The GetPrivateProfileString function searches the specified initialization file for a key that matches the name specified by the lpKeyName parameter under the section heading specified by the lpAppName parameter. If it finds the key, the function copies the corresponding string to the buffer. If the key does not exist, the function copies the default character string specified by the lpDefault parameter. A section in the initialization file must have the following form:
[section]
key=string
.
.
.
If lpAppName is NULL, GetPrivateProfileString copies all section names in the specified file to the supplied buffer. If lpKeyName is NULL, the function copies all key names in the specified section to the supplied buffer. An application can use this method to enumerate all of the sections and keys in a file. In either case, each string is followed by a null character and the final string is followed by a second null character. If the supplied destination buffer is too small to hold all the strings, the last string is truncated and followed by two null characters.
If the string associated with lpKeyName is enclosed in single or double quotation marks, the marks are discarded when the GetPrivateProfileString function retrieves the string.
The GetPrivateProfileString function is not case-sensitive; the strings can be a combination of uppercase and lowercase letters.
To retrieve a string from the WIN.INI file, use the GetProfileString function.
Windows NT: Calls to private profile functions may be mapped to the registry instead of to the specified initialization files. This mapping occurs when the initialization file and section are specified in the registry under the following keys:
HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows NT\CurrentVersion\IniFileMapping
This mapping is likely if an application modifies system-component initialization files, such as CONTROL.INI, SYSTEM.INI, and WINFILE.INI. In these cases, the GetPrivateProfileString function retrieves information from the registry, not from the initialization file; the change in the storage location has no effect on the function's behavior.
The Win32 profile functions (Get/WriteProfile*, Get/WritePrivateProfile*) use the following steps to locate initialization information:
HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows NT\CurrentVersion\IniFileMapping\myfile.ini
When looking at values in the registry that specify other registry locations, there are several prefixes that change the behavior of the .INI file mapping:
Registry Overview, Registry Functions, GetProfileString, WritePrivateProfileString