Another nice perl command line switch is -n. This builds the while(<>) loop for you. Example:

perl -i.bak -ne 'print unless $s{(split /\|/)[0]}++' infile

Note: more of these can be found in perlrun.

In reply to Re^3: how to remove duplicate based on the first column value by revdiablo
in thread how to remove duplicate based on the first column value by tariqahsan

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