Unless you're on a file system that allows for files which are sequences of lines (the only OS I know of which has such file systems and can run Perl is VMS), there are only two ways:
  1. Read the entire file into memory (for instance, into arrays), do all the slicing and dicing, and write out the result if you're done.
  2. Read in the file part by part, write it back to a different file after the slicing and dicing. When done, rename the new file to the original.

In reply to Re: Replacing, cutting, deleting lines in the file by JavaFan
in thread Replacing, cutting, deleting lines in the file by Jarek

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