Merlin’s Delphi Forge

Here is a list of the file extensions created by Delphi and what they all mean:

Extension Description
.dpr Delphi Project File. This is actually a Object Pascal source file. It is the main program for the application.
.~dp A backup file of the .dpr file before the last save operation.
.pas In Delphi, .pas files are always the source code to either a unit or a form. The main unit of an application is in the .dpr file.
.~pa A backup file of a .pas file.
.dfm These files are always paired with PAS files. The DFM file is the binary data (or text in Delphi 5+) used to set up initial data for components (IE, the properties you set in design mode rather than in code). Delphi 5 allows you to decide weather you want the form saved as text or in binary form. You can’t edit a .dfm file with a text editor, but if you open it in Delphi, you will see a text version of the contents and you can save it as text. To edit it with a text editor you first need to save it in text format. You can do this by opening a .dfm file in Delphi and saving it as a .txt file. To convert it back to binary form just open the .txt file in Delphi and save it as a .dfm file. 32 bit Delphi forms will not open properly if at all in Delphi 1.
.~df A backup file of a .dfm file.
.dcu A compiled unit, similar in concept to an .obj file.
.opt Project Options. I.E. compiler and linker settings, which form is the main form, what icon to use for the application, etc. Generally, everything you edit in the project options.
.dcu A compiled unit, similar in concept to an .obj file.
.res A Windows resource file. It is generated automatically by Delphi and required by the compilation process. You don’t need to worry about this file, but don’t delete it either.
.exe All of the above (except backup files, of course Cool) linked together into executable format.

Tags: About Delphi