GetProfileString
The GetProfileString
function retrieves the string associated with the specified key in the given
section of the WIN.INI file. This function is provided for compatibility with
16-bit Windows-based applications. Win32-based applications should store
initialization information in the registry.
DWORD GetProfileString(
LPCTSTR lpAppName, |
// address of
section name |
LPCTSTR lpKeyName, |
// address of key
name |
LPCTSTR lpDefault, |
// address of
default string |
LPTSTR lpReturnedString, |
// address of
destination buffer |
DWORD nSize |
// size of
destination buffer |
); |
|
Parameters
lpAppName
Pointer to a
null-terminated string that specifies the section containing the key. If this parameter
is NULL, the function copies all section names in the file to the supplied
buffer.
lpKeyName
Pointer to a
null-terminated string containing the key name whose associated string is to be
retrieved. If this parameter is NULL, the function copies all keys in the given
section to the supplied buffer. Each string is followed by a null character,
and the final string is followed by a second null character.
lpDefault
Pointer to a
null-terminated default string. If the lpKeyName key cannot be found in
the initialization file, GetPrivateProfileString copies the default
string to the lpReturnedString buffer. This parameter cannot be NULL.
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, Windows 95 strips any trailing blanks by
inserting a null character into the lpDefault string before copying it
to the lpReturnedString buffer.
Windows
NT: Windows NT 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.
lpReturnedString
Pointer to a
buffer that receives the character string.
nSize
Specifies the
size, in characters, of the buffer pointed to by the lpReturnedString
parameter.
Return Values
If the
function succeeds, the return value is the number of characters copied to the
buffer, not including the null-terminating 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.
Remarks
If the string
associated with the lpKeyName parameter is enclosed in single or double
quotation marks, the marks are discarded when the GetProfileString
function returns the string.
The GetProfileString
function is not case-sensitive; the strings can contain a combination of
uppercase and lowercase letters.
A section in
the WIN.INI file must have the following form:
[section]
key=string
.
.
.
An
application can use the GetPrivateProfileString
The lpDefault
parameter must point to a valid string, even if the string is empty (that is,
even if its first character is a null character).
Windows
NT:
Calls to
profile functions may be mapped to the registry instead of to the
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
When the
operation has been mapped, the GetProfileString 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:
1. Look in the registry for the name of the initialization file, say
myfile.ini, under IniFileMapping:
HKEY_LOCAL_MACHINE\Software\Microsoft\
Windows NT\CurrentVersion\IniFileMapping\myfile.ini
2. Look for the section name specified by lpAppName. This will
be a named value under myfile.ini, or a subkey of myfile.ini, or will not
exist.
3. If the section name specified by lpAppName is a named value
under myfile.ini, then that value specifies where in the registry you will find
the keys for the section.
4. If the section name specified by lpAppName is a subkey of
myfile.ini, then named values under that subkey specify where in the registry
you will find the keys for the section. If the key you are looking for does not
exist as a named value, then there will be an unnamed value (shown as
"<No Name>") that specifies the default location in the
registry where you will find the key.
5. If the section name specified by lpAppName does not exist as
a named value or as a subkey under myfile.ini, then there will be an unnamed
value (shown as "<No Name>") under myfile.ini that specifies
the default location in the registry where you will find the keys for the
section.
6. If there is no subkey for myfile.ini, or if there is no entry for
the section name, then look for the actual myfile.ini on the disk and read its
contents.
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:
! - this character forces all writes to go both to the registry and to
the .INI file on disk.
# - this character causes the registry value to be set to the value in
the Windows 3.1 .INI file when a new user logs in for the first time after
setup.
@ - this character prevents any reads from going to the .INI file on
disk if the requested data is not found in the registry.
USR: - this prefix stands for HKEY_CURRENT_USER, and the text after the
prefix is relative to that key.
SYS: - this prefix stands for HKEY_LOCAL_MACHINE\SOFTWARE, and the text
after the prefix is relative to that key.
See Also