The OPTARG environment variable is set by the getopts Command when it parses an option with an argument. It contains the argument, but not the option letter. For example, if the positional arguments are:
-a -bfoo +c -de
and getopts is invoked as follows:
while getopts ab:cdef opt
do
case $opt in
a) aflag=on ;;
b) bflag=$OPTARG ;;
+c) cflag=off ;;
c) cflag=on ;;
d) dflag=on ;;
e) eflag=on ;;
f) fflag=on ;;
esac
done
the resulting variable settings are:
| aflag | on |
| bflag | foo |
| cflag | off |
| dflag | on |
| eflag | on |
| fflag | (no change) |