[Overview][Constants][Types][Classes][Procedures and functions][Variables][Index] | Reference for unit 'sysutils' (#rtl)

# ExtractRelativePath

Extract a relative path from a filename, given a base directory.

## Declaration

Source position: finah.inc line 32

`function ExtractRelativePath(`
`const BaseName: UNICODESTRING;`
`const DestName: UNICODESTRING`
`):UNICODESTRING; function ExtractRelativePath(`
`const BaseName: RAWBYTESTRING;`
`const DestName: RAWBYTESTRING`
`):RAWBYTESTRING;`

## Description

ExtractRelativePath constructs a relative path to go from BaseName to DestName. If DestName is on another drive (Not on Unix-like platforms) then the whole Destname is returned.

Note that directories must end on a path delimiter for this function to work correctly. If not, the last part is stripped and treated as a file name.

## Errors

None.

## See also

ExtractFileName |  | Extract the filename part from a full path filename.
ExtractFilePath |  | Extract the path from a filename.
ExtractFileDir |  | Extract the drive and directory part of a filename.
ExtractFileDrive |  | Extract the drive part from a filename.
ExtractFileExt |  | Return the extension from a filename.

## Example

    Program Example35;

    { This program demonstrates the ExtractRelativePath function }

    Uses sysutils;

    Procedure Testit (FromDir,ToDir : String);

    begin
      Write ('From "',FromDir,'" to "',ToDir,'" via "');
      Writeln (ExtractRelativePath(FromDir,ToDir),'"');
    end;

    Begin
     Testit ('/pp/src/compiler/','/pp/bin/win32/ppc386/');
     Testit ('/pp/bin/win32/ppc386/','/pp/src/compiler/');
     Testit ('/pp/bin/win32/','/pp/src/compiler/ppcx386/');
     Testit ('/pp/bin/win32/','/pp/src/compiler/ppcx386');
     Testit ('/pp/bin/win32','/pp/src/compiler/ppcx386');
     Testit ('e:/pp/bin/win32/ppc386/','d:/pp/src/compiler/');
     Testit ('e:\pp\bin\win32\ppc386/','d:\pp\src\compiler/');
     Testit ('C:\FPC\3.0.2\','C:\FPC\3.0.2\');
     Testit ('C:\FPC\3.0.2\','C:\FPC\3.0.4rc1\');
     Testit ('Q:\','Q:\FPC\3.0.4rc1\');
    End.

Documentation generated on: May 14 2021