Title: Programmatically Get Parent Folder for a Specified File / Folder Name using Delphi
Delphi's RTL library exposes dozens of file name related functions and procedures.
You might be surprised that one function is "missing": how to get the parent folder (directory) for a specified file / folder name.
For example, for a given file named: "c:\My Documents\Pictures\ADP2008.gif", the parent folder is "c:\My Documents\Pictures".
If a folder is specified as "c:\My Documents\Pictures", the parent folder is then "c:\My Documents".
Therefore, parent directory is the directory that is one level up from the specified directory.
Path.GetParentFolder
The easiest way to create the "GetParentFolder" function yourself, is to use some of the existing RTL routines.
//returns the parent directory for the
//provided "path" (file or directory)
function GetParentDirectory(path : string) : string;
begin
result := ExpandFileName(path + '\..')
end;
Note: A backslash followed by two dots is a carryover from DOS that indicates the parent folder. The ExpandFileName RTL function retrieves the full path and filename of a specified (relative) file.
Note 2: the GetParentDirectory function will work even if the "path" parameter provided does *not* present an existing file or folder.