pg_controldata — display control information of a PostgreSQL database cluster
pg_controldata [option] [[ --pgdata  |   -D ] datadir]
   pg_controldata prints information initialized during
   initdb, such as the catalog version.
   It also shows information about write-ahead logging and checkpoint
   processing.  This information is cluster-wide, and not specific to any one
   database.
  
   This utility can only be run by the user who initialized the cluster because
   it requires read access to the data directory.
   You can specify the data directory on the command line, or use
   the environment variable PGDATA.  This utility supports the options
   -V and --version, which print the
   pg_controldata version and exit.  It also
   supports options -? and --help, which output the
   supported arguments.
  
PGDATADefault data directory location
PG_COLOR
      Specifies whether to use color in diagnostic messages. Possible values
      are always, auto and
      never.