Re: capturing print_message to a file

This module I couldn't find (6.4.1):


65 ?- check_installation:run_collect_messages(cp:test_member_con_instance, Result, Messages). 
ERROR: [Thread 2] toplevel: Undefined procedure: check_installation:run_collect_messages/3 (DWIM could not correct goal) 

[debug] 67 ?- [library(check_installation)]. 
ERROR: [Thread 2] source_sink `library(check_installation)' does not exist

The code exhibits an interesting use of asserta to make a temporary 
hook.
The predicate would be nice to have documented and in a public 
module not related to installation. 

Anyway by now I have put together similar:


%% the main thing is I dump to stdout so I can redirect it.
user:message_hook(_Message, trace, Lines) :- maplist(spew, Lines).

spew(flush) :- !,nl.
spew(X) :- atom(X), !, write(X).
spew(X-Y) :- format(X, Y).
spew(X) :- format('Unknown: ~w', [X]).


%% turn on trace and redirect it:
:- meta_predicate chr_trace_log(:).
chr_trace_log(Method) :-
once(chr_leash(none))
, setup_call_cleanup((chr_trace
                     , debug
                     , tell('chr_trace.log'))
, Method
, (flush
  , told
  , chr_notrace)).


Alan Baljeu


----- Original Message -----
From: Jan Wielemaker <[email protected]>
To: Alan Baljeu <[email protected]>; Prolog <[email protected]>
Cc: 
Sent: Thursday, April 3, 2014 3:50:26 AM
Subject: Re: [SWIPL] capturing print_message to a file

On 04/02/2014 10:26 PM, Alan Baljeu wrote:

> I see all this stuff flying by onscreen, so I want a file.  It's not
> stdout so I guess it's stderr.  Is redirecting the stream the
> intended way to go, or is the message_hook stuff the way to go?

Maybe this:

http://www.swi-prolog.org/pldoc/doc/home/vnc/prolog/lib/swipl/library/check_installation.pl?show=src#run_collect_messages/3

    Cheers --- Jan


> 
> Alan Baljeu -------------- next part -------------- HTML attachment
> scrubbed and removed _______________________________________________ 
> SWI-Prolog mailing list [email protected] 
> https://lists.iai.uni-bonn.de/mailman/listinfo.cgi/swi-prolog

> 
-------------- next part --------------
HTML attachment scrubbed and removed