AWK正则表达式不起作用

Question

I have a very simple awk script that is supposed to extrapolate some log lines with a regex. I'm testing it but if I do this:

awk -F ' ' '$5 ~ /MyClassName/ {p=1} p {print $5}' myLogFile.log

I get lines from other classes even if the output should be only lines containing MyClassName.

Can anyone explain me what's wrong with this?

Thank you.

Answer 1

You can avoid using p altogether and AFAIK setting FS ( -F ) to a literal space is the same as not setting it as all:

awk '$5 ~ /MyClassName/ {print $5}' myLogFile.log

And since you are only interested in column 5 you should be able to use:

awk '{$0=$5} /MyClassName/' myLogFile.log

Answer 2

您永远不会将p重置为零。

awk -F ' ' '{p=0} $5 ~ /MyClassName/ {p=1} p {print $5}' myLogFile.log