Hi guys:
Just a question really. In the code below (not mine - I'm learning about handling flock differently), I notice the use of a semi-colon for a write, but not in the other cases.

The code works fine, just wondering why the difference?

Code:

# Variable $flock = "0";  # Set to to 1 for Unix ### No semi-colon for reading and on >> appends. if ($flock) {flock(DATABASE, 2)} etc-etc..... ### Why the semi-colon on this one? Is it becuz of the > type write? open (DATABASE, ">".$file); if ($flock) {flock(DATABASE, 2);} etc-etc.....

Cheers - Ted


The semi-colon has nothing to do with the use of flock or anything else for that matter.

The last line (or in this case the only line) of a block of code: {}, does not need a semi-colon, it's optional. In my opinion, for consitancy sake you should always put one.  

Hard core perl coders will tell you to use the Fcntl module and import the flock constants into your program. I am a bit ambivalent on this issue but I tend to use Fcntl too and import the symbolic names, in some cases it might be necessary although I am not sure about that, maybe Graham knows. See the flock() function and the Fcntl module for more details.

Hi Kevin, Thanks. I usually just do a
Code:

# flock(DFILE, 2);

Then remove the comment when I put it on my live Unix server. My local testbed is Indigo perl on a Windows PC, so it's commented out there. Which is okay if there's just one, But - when there are hundreds or thousands of lines of code, with a bunch of flocks in, I figured I need a more efficient way to do it - hence the variable option.

I'll use the semi-colon as suggested.

Cheers - Ted

It was evident what you were doing by this line:

# Variable
$flock = "0";  # Set to to 1 for Unix

Been there, done that, too. You can make that dynamic:

my $flock = ($^O =~ /MSwin32/i) ? 1 : 0;

Then you don't have to comment it out and it will work on Windows and Unix/Linux.



That's neat  Thanks Kevin.

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