SWI-Prolog 5.11.18 Reference Manual: Section 2.2

## 2.2 The user's initialisation file

After the necessary system initialisation the system consults (see consult/1) the user's startup file. The base-name 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.

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