# Find the version number of a module
perl -le 'eval "require $ARGV[0]" and print $ARGV[0]->VERSION' Some::Module


# Check if a module is installed
perl -le 'print 0 + eval "require $ARGV[0]" ' Some::Module

# Or this mnemonic cheat
perl -exists -MSome::Module


# Plain silly
$ perl -wevest
String vest may clash with future fashion at -e line 1.