Closing a system process after file creation (was: One for the Wisest Monks)

[Anonymous Monk]

I am using a one up counter from a file to make ID keys for a db file. I have found a way to dynamically create a .dat file using this one up counter so I can have a log seperate from the database that coincides. I do this with the following command:

system "cat > $num.bat"; #(creates 19.bat if the one up counter is at 19)

now the question....how can I add a command in this string that will not only create the new file but close it automatically so the process dies?

update by boo_radley : title change

[Zaxo]

Your system call is waiting for input from stdin. You could call 'touch' instead, but how about a pure perl solution?

{
    my $fh;
    open $fh, '>', "/path/to/${num}.bat" or die $!;
}

You are likely to want a more economical representation of your counter, sooner or later. You should think about flock when you design it.

After Compline,
Zaxo

[TexasTess]

I've tried this..or a reasonable facimile...I'll try again when I go back to work...perhaps I was making a permissions oversight.

This command will create a file called $(num).bat? in the directory listed in the path?

Sure hope it works!! I'll let ya know tomorrow!

Thanks!

[Matts]

If you really want to use system commands and not straight perl, try:

system "touch $num.bat";

Has the advantage of not doing anything to the file (except changing it's timestamp) if it already exists.

[merlyn]

system "touch $num.bat";

But that unnecessarily starts a separate process, and is subject to security issues regarding the contents of $num.

Much safer and faster:

open DUMMY, ">>$num.bat";
close DUMMY;

-- Randal L. Schwartz, Perl hacker

[Abigail-II]

    system touch => "$num.bat";

doesn't suffer from security issues regarding the content of $num. As for "much faster", I'm not quite convinced. You're doing disk I/O here, and that's likely to be the bottleneck anyway.

Abigail

[TexasTess]

I like it!

[TexasTess]

Have it implemented and it's working GREAT! Thanks again!

TexasTess
"Great Spirits Often Encounter Violent Opposition From Mediocre Minds" --Albert Einstein

[TexasTess]

BTW didn't mean for this to be anonymous....forgot to log in

[Aristotle]

Just a hint: change the site scheme in your User settings - then it is immediately visible when you're logged in and when not. :-)
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