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How to get the parent directory path of a path in FreePascal/Lazarus?

I have a path to a directory saved as a string, and wanted to know how I can easily and robustly extract the parent directory from this string?

I tried to see if there is some method for this in FileUtil and SysUtils, but haven't found anything so far.

Solution

  • The simplest way is to find the last path delimiter character and trim the source string. BTW there are some alternative:

    program Project1;

uses
    sysutils;
var
    sExe: string;
    sParent: string;
    sParentProper: string;
begin
    sExe := ExtractFilePath(ParamStr(0)); // Get executable directory
    Writeln(sExe);
    sParent := IncludeTrailingPathDelimiter(sExe) + '..' + PathDelim; // Make parent path for executable
    Writeln(sParent);
    sParentProper := ExpandFileName(sParent); // Get absolute path based on relative path
    WriteLn(sParentProper);
    Readln;
end.

    And output is:

    C:\Users\nd\AppData\Local\Temp\
C:\Users\nd\AppData\Local\Temp\..\
C:\Users\nd\AppData\Local\

    So using this technique the proper way is ExpandFileName(IncludeTrailingPathDelimiter(sBasePath) + '..')

    PS: We are using only sysutils unit so it is pure FPC solution and it is not require any LCL libraries.