There are some advantages to working in-place over creating a temporary file:

This is pretty close to what the -i commandline switch does for Perl one liners

-i is closer to 

open(my $fh_in,  '<', $qfn);
unlink($qfn);
open(my $fh_out, '>', $qfn);
...

[download]

for now.

In reply to Re^3: Inserting a line in the middle of a text by ikegami
in thread Inserting a line in the middle of a text by goude

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