## 2.2 The user's initialisation file

After the system initialisation, the system consults (see consult/1) the user's startup file. The basename of this file follows conventions of the operating system. On MS-Windows, it is the file `pl.ini` and on Unix systems `.plrc`. The file is searched using the file_search_path/2 clauses for `user_profile`. The table below shows the default value for this search path. The phrase <appdata> refers to the Windows CSIDL name for the folder. The actual name depends on the Windows language. English versions typically use `ApplicationData`. See also win_folder/2

| Unix | Windows
local | `.` | `.`
home | ``~`` | <appdata>/SWI-Prolog

After the first startup file is found it is loaded and Prolog stops looking for further startup files. The name of the startup file can be changed with the `-f file' option. If File denotes an absolute path, this file is loaded, otherwise the file is searched for using the same conventions as for the default startup file. Finally, if file is `none`, no file is loaded.

The installation provides a file `customize/dotplrc` with (commented) commands that are often used to customize the behaviour of Prolog, such as interfacing to the editor, color selection or history parameters. Many of the development tools provide menu entries for editing the startup file and starting a fresh startup file from the system skeleton.

See also the -s (script) and -F (system-wide initialisation) in section 2.4 and section 2.3.