The following predicates are available if SWI-Prolog is linked to the 
GNU readline library. This is by default the case on non-Windows 
installations and indicated by the Prolog flag readline.89plwin.exe 
uses its own history system and does not support these 
predicates. See also readline(3)
- rl_read_init_file(+File)
- 
Read a readline initialisation file. Readline by default reads
 /.inputrc. This predicate may be used to read alternative 
readline initialisation files.
- rl_add_history(+Line)
- 
Add a line to the Control-P/Control-N history system of the readline 
library.
- rl_write_history(+FileName)
- 
Write current history to FileName. Can be used from at_halt/1 
to save the history.
- rl_read_history(+FileName)
- 
Read history from FileName, appending to the current history.