in reply to incrementing the file

There's a large number of file test unary operators which will check files for existence, size, writability and so on.

It's unclear whether you're renaming an existing file or generating a new, unique filename. If the former, File::Copy may be your best bet (there is a rename function but it has documented limitations).

-- Ken

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Re^2: incrementing the file
by abcdefg (Acolyte) on Feb 21, 2012 at 21:10 UTC

    Hi Ken, I am generating a new file which has name of previous file and a numerical suffix which is incremented everytime... eg file 1 then file 2.....

[reply]

      You can try starting with a "templated" filename and increment it until you get past all the existing files: 

      my $fn = "output000";
$fn++ while -e $fn;

      [download]

      At that point, you'll have a filename that is just past the last one of that pattern. Minor caveat: make sure you have enough zeroes at the end of the template - or you'll start incrementing the characters. Yes, really. 

      ben@feynman:~$ perl -wle'$number = "one"; $number++ for 1..3624; print
+ $number'
two

      [download]

      :) 

      -- 
I hate storms, but calms undermine my spirits.
 -- Bernard Moitessier, "The Long Way"
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