[Gambas-user] Process/Shell Bug

[Benoit Minisini]

On Monday 28 August 2006 14:13, Timothy Marshal-Nichols wrote:
> > -----Original Message-----
> > From: gambas-user-bounces at lists.sourceforge.net
> > [mailto:gambas-user-bounces at lists.sourceforge.net]On Behalf Of Benoit
> > Minisini
> > Sent: Monday, 28 August 2006 10:51
> > To: mailing list for gambas users
> > Subject: Re: [Gambas-user] Process/Shell Bug
> >
> > On Monday 28 August 2006 09:42, Timothy Marshal-Nichols wrote:
> > > Hello Benoit,
> > >
> > > Just thought I should add this to your TO-DO list. I have been
> >
> > meaning to
> >
> > > report this bug for some time. It was Stefano's comments that
> >
> > suggested you
> >
> > > might be looking at the SHELL and EXEC functions. So now might be a
> > > good time to look at this bug.
> > >
> > > To see the bug open the Gambas Console in the example projects
> >
> > and run it.
> >
> > > (The bug in not in the example project. I found the bug in my own
> > > projects.) Type this command in the Gambas Console TextBox:
> > >
> > > 	ls -l $HOME | cat -n
> > >
> > > In this command we use 'cat -n' just to number the lines. (This
> >
> > will make
> >
> > > it easier to see the bug later.) You should see nothing wrong. Now try
> > > a command that returns a lot more data. For example:
> > >
> > > 	ls -l /proc | cat -n
> > > 	lsof | cat -n
> > > 	ps aux | cat -n
> > > 	find $HOME -type d | cat -n
> > >
> > > After about 30 to 70 lines some lines have been split across two lines.
> > > This depends on the length of a lines returned. The problem
> >
> > appears to be
> >
> > > LINE INPUT #LAST splitting a line in two where it should have
> >
> > returned one.
> >
> > > Oddly sometimes after about 500 (approx) lines the split lines
> >
> > do not occur
> >
> > > anymore. The bug is when a lot of lines are returned. When only a small
> > > amount of data is returned there is not problem.
> > >
> > > The 'cat -n' in the above commands is just to make it easier to see the
> > > bug.
> > >
> > > I have just been looking at Gambas version 1.9.40 (on SUSE
> >
> > 10.1) and 1.0.16
> >
> > > (on Fedora 4). Sorry but this bug is in the stable version as well.
> > >
> > > Thanks
> > >
> > > 8-{)} Timothy Marshal-Nichols
> > > <mailto: timothy.marshal-nichols at ...247...>
> >
> > Just a remark to beginning: but why each time you send a mail to the
> > mailing-list, your mail is always attached to a non-related
> > thread? Is it you
> > fault, or is there a bug in the mailing-list or in KMail?
> >
> > Well, now let's see your problem.
> >
> > Actually this is not a Gambas bug, but a buggy example!
> >
> > You should never use LINE INPUT to read the process output, but
> > READ instead,
> > because if there is no newline character in the pipe that receives the
> > process output, then LINE INPUT will assume that the end of the
> > pipe is like
> > a new line.
>
> Then why have this as an example? Also the help for both SHELL and EXEC
> show using LINE INPUT to read the process. This is just misleading.
>

Maybe I made this mistake because at the beginning, I thought that I could 
buffered the process output until I meet a newline, so that I'm sure that 
LINE INPUT will always read a true line. But this was a bad idea, as a 
process may never print a newline...

Anyway, I will fix the documentation. Sorry for that!

Regards,

-- 
Benoit Minisini