One obvious problem -- put the mkdir inside the if statement: 
if ($line =~ /mydir/) {
  $directory = ...
  mkdir $directory, 0775;
}

[download]
You only want to call mkdir if the line matches.

Also, passing "\n" to mkdir doesn't make any sense here. The second argument to mkdir is a permission mode mask. See the comments on perldoc -f mkdir for more discussion on how this parameter works.

Finally, you should get accustom to using the three parameter version of open: 

open(FILE, '<', $ARGV[0]);

[download]
This is much safer.

In reply to Re^3: Create new directories by pc88mxer
in thread Create new directories by ibaboom

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