You can add a little logic to the one-liner to cope with more general cases where some ERROR messages don't span two lines (assuming messages all start with a timestamp).

perl -ne 'sub BEGIN {$l="";}$l=$_, next unless /ERROR/;print /^[^12]/ 
+? "$l$_" : $_;$l=$_;' some.log

[download]

Not Y3K compliant.

JohnGG

Note: something is eating the square brackets around the character class ^12 for some reason. Code tags don't help.

In reply to Re^3: need to extract top and bottom lines... by johngg
in thread need to extract top and bottom lines... by Anonymous Monk

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