Re: using a variable to help define a regular expression

tbh wrote

>>>>   base=f30
>>>>   gawk 'tolower($5) ~ /^\/'"$base"'\// {

in this case $base is a shell variable. It is inserted into the gawk
program by splitting it into 2 parts
	'tolower($5) ~ /^\/
and	'\// {....'
The variable is inserted by the shell in that case. That means awk
sees a regex constant /.../


> $ ... | gawk -v base="f30" 'BEGIN {print base} (tolower($5) ~
/^\/f30\//) 
>[...]

here you are passing the value into a awk variable and want to
dynamically create the regex inside the awk program.

A dynamic regex is a string. So you have to use: 
	... ~ "^\/" base "\/"
-- 

Lorenz