How to flush history ?

How to flush history ?

[Roberto Rosetti]

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Hi all,

I'm wondering how to flush the recent readline history to a file. I need
this feature for an educational project.
The purpose is to permit the REPL user to save his entire history with a
simple command. Something like (flush-history <params>)
I've read something about (loggin logger) module but there are not
examples about hooks and coding.
I'm not a guile hacker,I'm still learning.. 
Thanks in advance.

-- 

Roberto Rosetti

OpenPGP Public key: 30575161

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Re: How to flush history ?

[Neil Jerram]

Roberto Rosetti <rob.rosetti@gmail.com> writes:

> Hi all,
>
> I'm wondering how to flush the recent readline history to a file. I need this
> feature for an educational project.
> The purpose is to permit the REPL user to save his entire history with a simple
> command. Something like (flush-history <params>)
> I've read something about (loggin logger) module but there are not examples
> about hooks and coding.
> I'm not a guile hacker,I'm still learning..
> Thanks in advance.

Hi Roberto,

The readline history is already saved to a file, ~/.guile_history.
Does that provide what you need?

(I'm not sure offhand if it is saved after every line is entered, or
when you quit Guile; but maybe that difference is not important for
you anyway.)

     Neil

Re: How to flush history ?

[Roberto Rosetti]

On  friday, 14/08/2009 alle 22.39 +0100, Neil Jerram writes:
> 
> > Hi all,
> >
> > I'm wondering how to flush the recent readline history to a file. I need this
> > feature for an educational project.
> > The purpose is to permit the REPL user to save his entire history with a simple
.....
> Hi Roberto,
> 
> The readline history is already saved to a file, ~/.guile_history.
> Does that provide what you need?
> 
> (I'm not sure offhand if it is saved after every line is entered, or
> when you quit Guile; but maybe that difference is not important for
> you anyway.)

>      Neil

Well, thanks for the answer Neil. I know about the existence of
~/.guile_history, but my problem is more complex: I need a hook to the
history buffer, like a port or something. A way to flush the history to
its file at a given command. Just to grab everything written before and
then manipulate (a copy of) the history file.
For the moment, I've written a simple wrapper for readline, that process
the input and save every command to a specific text file, after checking
it for correctness. 
An alternate solution may be to change the GUILE_HISTORY envrironment
variable at run-time, but I thing it's not an elegant solution at all.

Rob


-- 

Roberto Rosetti

OpenPGP Public key: 30575161

Re: How to flush history ?

[Neil Jerram]

Roberto Rosetti <rob.rosetti@gmail.com> writes:

> Well, thanks for the answer Neil. I know about the existence of
> ~/.guile_history, but my problem is more complex: I need a hook to the
> history buffer, like a port or something. A way to flush the history to
> its file at a given command. Just to grab everything written before and
> then manipulate (a copy of) the history file.
> For the moment, I've written a simple wrapper for readline, that process
> the input and save every command to a specific text file, after checking
> it for correctness. 

Well I wasn't aware of it before, but I just looked at
guile-readline/readline.c and noticed that there is a write-history
primitive:

SCM_DEFINE (scm_write_history, "write-history", 1, 0, 0, 
            (SCM file),
"")
#define FUNC_NAME s_scm_write_history
{
  char *filename;
  SCM ret;

  filename = scm_to_locale_string (file);
  ret = scm_from_bool (!write_history (filename));
  free (filename);
  return ret;
}
#undef FUNC_NAME

Is that a solution for you?

Regards,
        Neil