Checking filehandles

[redgenie]

Hey everyone,

Does anyone know how to check if a filehandle is currently open for writing (or open for that matter) see below:

$SIG{'INT'} = 'SIGNALHANDLER';

open FILE, ">/somefile";
# Some one presses Ctrl C here!
close FILE;
# Some one may press Ctrl C here!


sub SIGNAL HANDLER {

        if (FILE) {    <-- This bit wrong
                close FILE;
        } else {
                 print "Filehandle wasn't open.";
        }

        exit;
}

Any help would be greatly appreciated

 

[MikeLacey]

Obvious wrong bit in your code is that:

sub SIGNAL HANDLER {

should be:

sub SIGNALHANDLER {

That may just be a typo here though.

I would try and use the filehandle, wrapping that bit of code in an eval(), if I wanted to test its state.

Mike

"Deliver me from the bane of civilised life; teddy bear envy."

Want to get great answers to your Tek-Tips questions? Have a look at faq219-2884

 

[rharsh]

This isn't entirely bulletproof, but it should work for what you're trying to do.

open FH, "< somefile.txt" or die;

if (fileno(FH)) {print "Filehandle is open.\n";}
else {print "Filehandle is closed.\n";}

close FH;

if (fileno(FH)) {print "Filehandle is open.\n";}
else {print "Filehandle is closed.\n";}

 

[redgenie]

Oops, sorry for that yes it was just a typo in here. I'll give your eval() suggestions a try.

 

[redgenie]

Thanks, rharsh. Not sure if that works when writing I thought I had looked at that but I'll give it another try.

 

[MikeLacey]

rharsh's fileno() solution looks better to me.

Mike

"Deliver me from the bane of civilised life; teddy bear envy."

Want to get great answers to your Tek-Tips questions? Have a look at faq219-2884

 

[redgenie]

Many thanks for that rharsh, it does work with files open for writing.

Thank you very much for your help!