Re^3: need to extract top and bottom lines...

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.~~

Comment on Re^3: need to extract top and bottom lines... Download Code

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Re^4: need to extract top and bottom lines... by johngg (Canon) on Dec 16, 2004 at 11:20 UTC
Oops, something ate the square brackets around the negated character class ^12. Maybe code tags will help, maybe not. `perl -ne 'sub BEGIN {$l="";}$l=$_, next unless /ERROR/;print /^[^12]/ +? "$l$_" : $_;$l=$_;' some.log` [download] Johngg	[reply] [d/l]