Usage:

  /usr/bin/pg_md5 [OPTIONS]
  /usr/bin/pg_md5 <PASSWORD>

  --prompt, -p         Prompt password using standard input.
  --md5auth, -m        Produce md5 authentication password.
  --username, -u USER  When producing a md5 authentication password,
                       create the pool_passwd entry for USER.
  --config-file, -f CONFIG-FILE  Specify pgpool.conf.
  --input-file, -i INPUT-FILE  Specify file containing username and password pairs.
  --help, -h           This help menu.

Warning: At most 128 characters are allowed for input.
Warning: Plain password argument is deprecated for security concerns
         and kept for compatibility. Please prefer using password
         prompt or input file method.