Duplicate specification "V" for option "v" Unknown option: help Usage: /usr/bin/json_pp [-V] [-f from_format] [-t to_format] [-json_opt options_to_json1[,options_to_json2[,...]]]
Examples (2) from the manual page, untested
perl -e'print q|{"foo":"あい","bar":1234567890000000000000000}|' |\perl -e'print q|{"foo":"あい","bar":1234567890000000000000000}|' |\