bash - parse argument list in a file

Question

I have a script called foo.sh that contains something like

exec myapp -o size=100m -f 

Any idea how to create another script that parses foo.sh and retrieves the value of size? One can assume myapp only appears once in foo.sh, but the order of size argument can appear anywhere in the argument list

Thanks

Answer 1

With grep in a shell :

$ grep -oP 'myapp.*?size=\K\d+m' foo.sh
100m

With awk in a shell :

$ awk -F'size='  '{sub(/ -f/, "");print $2}' foo.sh
100m

or

$ awk '{print gensub(/.*size=([0-9]+m).*/, "\\1", $0)}' foo.sh
100m

With perl in a shell :

$ perl -lne 'print $1 if /exec.*?size=(\d+m)/' foo.sh
100m

Or using a shell funny trick :

$ declare $(grep -oP "\b\w+=\w+\b" foo.sh)
$ echo $size
100m