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perl -ne 'print unless $seen{$_}++' data.txt Or, if you must have a useless use of cat:
cat data.txt | perl -ne 'print unless $seen{$_}++' Here's an awk translation, for systems that lack Perl:
awk '{ if (!seen[$0]++) print }'seen[$0]++' data.txt cat data.txt | awk '{ if (!seen[$0]++) print }'seen[$0]++' perl -ne 'print unless $seen{$_}++' data.txt Or, if you must have a useless use of cat:
cat data.txt | perl -ne 'print unless $seen{$_}++' Here's an awk translation, for systems that lack Perl:
awk '{ if (!seen[$0]++) print }' data.txt cat data.txt | awk '{ if (!seen[$0]++) print }' perl -ne 'print unless $seen{$_}++' data.txt Or, if you must have a useless use of cat:
cat data.txt | perl -ne 'print unless $seen{$_}++' Here's an awk translation, for systems that lack Perl:
awk '!seen[$0]++' data.txt cat data.txt | awk '!seen[$0]++' perl -ne 'print unless $seen{$_}++' data.txt Or, if you must have a useless use of cat:
cat data.txt | perl -ne 'print unless $seen{$_}++' Here's an awk translation, for systems that lack Perl:
awk '{ if (++seen[$0] == 1!seen[$0]++) { print $0 } }' data.txt cat data.txt | awk '{ if (++seen[$0] == 1!seen[$0]++) { print $0 } }' perl -ne 'print unless $seen{$_}++' data.txt Or, if you must have a useless use of cat:
cat data.txt | perl -ne 'print unless $seen{$_}++' Here's an awk translation, for systems that lack Perl:
awk '{ if (++seen[$0] == 1) { print $0 } }' data.txt cat data.txt | awk '{ if (++seen[$0] == 1) { print $0 } }' perl -ne 'print unless $seen{$_}++' data.txt Or, if you must have a useless use of cat:
cat data.txt | perl -ne 'print unless $seen{$_}++' Here's an awk translation, for systems that lack Perl:
awk '{ if (!seen[$0]++) print }' data.txt cat data.txt | awk '{ if (!seen[$0]++) print }' perl -ne 'print unless $seen{$_}++' data.txt Or, if you must have a useless use of cat:
cat data.txt | perl -ne 'print unless $seen{$_}++' Here's an awk translation, for systems that lack Perl:
awk '{ if (++seen[$0] == 1) { print $0 } }' data.txt cat data.txt | awk '{ if (++seen[$0] == 1) { print $0 } }' perl -ne 'print unless $seen{$_}++' data.txt Or, if you must have a useless use of cat:
cat data.txt | perl -ne 'print unless $seen{$_}++' perl -ne 'print unless $seen{$_}++' data.txt Or, if you must have a useless use of cat:
cat data.txt | perl -ne 'print unless $seen{$_}++' Here's an awk translation, for systems that lack Perl:
awk '{ if (++seen[$0] == 1) { print $0 } }' data.txt cat data.txt | awk '{ if (++seen[$0] == 1) { print $0 } }'