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How to remove lines that are doubled only after line containing some string - linux/bash

as mentioned in title. I found a command that works so lines that are doubled are removed:

perl -i.bak -ne 'print if ! $x{$_}++' ~/.bashrc

but how to achieve that only after line that contains specific string, sth like:

if line is after line with string "hello"
    perl -i.bak -ne 'print if ! $x{$_}++' ~/.bashrc

I am trying to use bash for it.

Solution

  • You can use the range extraction operator ..:

    perl -i.bak -ne 'print if //../hello/ or !$x{$_}++' ~/.bashrc