Re: using a variable to help define a regular expression

"Lorenz" wrote
> 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 "\/"

thanks for your patience. i think i get it all now!

cheers, Tim