Question

Is there a way to find the size(memory used) of shell variable from command line, without using C ?

Answer 1

wc can tell you how many characters and bytes are in a variable, and bash itself can tell you how many elements are in an array. If what you’re looking for is how large bash’s internal structures are for holding a specific variable then I don’t believe that’s available anywhere.

$ foo=42
$ bar=(1 2 3 4)
$ echo -n "$foo" | wc -c -m
      2       2
$ echo "${#bar[@]}"
4