elvistudio

Hello!
Could you tell me why do this command's output is zero ("0")? Many
lines of file 'trace' contain the string "Exception"...

awk 'BEGIN{i=""}$0 ~ /Exception/{i+=$0}END{print i}' trace (or awk
'BEGIN{i=""}{if ($0 ~ /Exception/) i+=$0}END{print i}' trace)

Thanks!

vassilis

Try this out:

awk 'BEGIN{i=""}
$0 ~ /Exception/ { printf "%s = %.6g\n", $0, $0; i += $0 }
END {print i}' trace

What do you think?

ed morton

+= is for arithmetic addition, not string concatentation.

Ed.

chris f.a. johnson

What are you trying to do?

If you want to count the number of lines containing Exception:

awk '/Exception/ { ++i } END { print i }' trace

If you want to concatenate all lines containing Exception:

awk '/Exception/ { i = i $0 } END { print i }' trace

Or, if you want to preserve the lines:

awk '/Exception/ { i = i $0 "\n" } END { printf "%s", i }' trace --
Chris F.A. Johnson, author | <http://cfaj.freeshell.org>
Shell Scripting Recipes: | My code in this post, if any,
A Problem-Solution Approach | is released under the
2005, Apress | GNU General Public Licence