4.38 Creating a Protocol of the User Interaction

SWI-Prolog offers the possibility to log the interaction with the user on a file.^{162A similar facility was added to Edinburgh C-Prolog by Wouter Jansweijer.} All Prolog interaction, including warnings and tracer output, are written to the protocol file.

protocol(+File)

Start protocolling on file File. If there is already a protocol file open, then close it first. If File exists it is truncated.

protocola(+File)

Equivalent to protocol/1, but does not truncate the File if it exists.

noprotocol

Stop making a protocol of the user interaction. Pending output is flushed on the file.

protocolling(-File)

True if a protocol was started with protocol/1 or protocola/1 and unifies File with the current protocol output file.