pg_ctl — initialize, start, stop, or control a PostgreSQL server
pg_ctl  init[db]  [-D datadir] [-s] [-o initdb-options]
pg_ctl  start  [-D datadir] [-l filename] [-W] [-t seconds] [-s] [-o options] [-p path] [-c]
pg_ctl  stop  [-D datadir] [-m
        s[mart]  |   f[ast]  |   i[mmediate]  
   ] [-W] [-t seconds] [-s]
pg_ctl  restart  [-D datadir] [-m
        s[mart]  |   f[ast]  |   i[mmediate]  
   ] [-W] [-t seconds] [-s] [-o options] [-c]
pg_ctl  reload  [-D datadir] [-s]
pg_ctl  status  [-D datadir]
pg_ctl  promote  [-D datadir] [-W] [-t seconds] [-s]
pg_ctl  logrotate  [-D datadir] [-s]
pg_ctl  kill   signal_name   process_id 
On Microsoft Windows, also:
pg_ctl  register  [-D datadir] [-N servicename] [-U username] [-P password] [-S
        a[uto]  |   d[emand]  
   ] [-e source] [-W] [-t seconds] [-s] [-o options]
pg_ctl  unregister  [-N servicename]
pg_ctl is a utility for initializing a PostgreSQL database cluster, starting, stopping, or restarting the PostgreSQL database server (postgres), or displaying the status of a running server. Although the server can be started manually, pg_ctl encapsulates tasks such as redirecting log output and properly detaching from the terminal and process group. It also provides convenient options for controlled shutdown.
   The init or initdb mode creates a new
   PostgreSQL database cluster, that is,
   a collection of databases that will be managed by a single
   server instance.  This mode invokes the initdb
   command.  See initdb for details.
  
   start mode launches a new server.  The
   server is started in the background, and its standard input is attached
   to /dev/null (or nul on Windows).
   On Unix-like systems, by default, the server's standard output and
   standard error are sent to pg_ctl's
   standard output (not standard error).  The standard output of
   pg_ctl should then be redirected to a
   file or piped to another process such as a log rotating program
   like rotatelogs; otherwise postgres
   will write its output to the controlling terminal (from the
   background) and will not leave the shell's process group.  On
   Windows, by default the server's standard output and standard error
   are sent to the terminal.  These default behaviors can be changed
   by using -l to append the server's output to a log file.
   Use of either -l or output redirection is recommended.
  
   stop mode shuts down the server that is running in
   the specified data directory.  Three different
   shutdown methods can be selected with the -m
   option.  “Smart” mode disallows new connections, then waits
   for all existing clients to disconnect and any online backup to finish.
   If the server is in hot standby, recovery and streaming replication
   will be terminated once all clients have disconnected.
   “Fast” mode (the default) does not wait for clients to disconnect and
   will terminate an online backup in progress.  All active transactions are
   rolled back and clients are forcibly disconnected, then the
   server is shut down.  “Immediate” mode will abort
   all server processes immediately, without a clean shutdown.  This choice
   will lead to a crash-recovery cycle during the next server start.
  
   restart mode effectively executes a stop followed
   by a start.  This allows changing the postgres
   command-line options, or changing configuration-file options that
   cannot be changed without restarting the server.
   If relative paths were used on the command line during server
   start, restart might fail unless
   pg_ctl is executed in the same current
   directory as it was during server start.
  
   reload mode simply sends the
   postgres server process a SIGHUP
   signal, causing it to reread its configuration files
   (postgresql.conf,
   pg_hba.conf, etc.).  This allows changing
   configuration-file options that do not require a full server restart
   to take effect.
  
   status mode checks whether a server is running in
   the specified data directory. If it is, the server's PID
   and the command line options that were used to invoke it are displayed.
   If the server is not running, pg_ctl returns
   an exit status of 3.  If an accessible data directory is not
   specified, pg_ctl returns an exit status of 4.
  
   promote mode commands the standby server that is
   running in the specified data directory to end standby mode
   and begin read-write operations.
  
   logrotate mode rotates the server log file.
   For details on how to use this mode with external log rotation tools, see
   Section 24.3.
  
   kill mode sends a signal to a specified process.
   This is primarily valuable on Microsoft Windows
   which does not have a built-in kill command.  Use
   --help to see a list of supported signal names.
  
   register mode registers the PostgreSQL
   server as a system service on Microsoft Windows.
   The -S option allows selection of service start type,
   either “auto” (start service automatically on system startup)
   or “demand” (start service on demand).
  
   unregister mode unregisters a system service
   on Microsoft Windows.  This undoes the effects of the
   register command.
  
-c--core-filesAttempt to allow server crashes to produce core files, on platforms where this is possible, by lifting any soft resource limit placed on core files. This is useful in debugging or diagnosing problems by allowing a stack trace to be obtained from a failed server process.
-D datadir--pgdata=datadir
        Specifies the file system location of the database configuration files.  If
        this option is omitted, the environment variable
        PGDATA is used.
       
-l filename--log=filename
        Append the server log output to
        filename.  If the file does not
        exist, it is created.  The umask is set to 077,
        so access to the log file is disallowed to other users by default.
       
-m mode--mode=mode
        Specifies the shutdown mode.  mode
        can be smart, fast, or
        immediate, or the first letter of one of
        these three.  If this option is omitted, fast is
        the default.
       
-o options--options=options
        Specifies options to be passed directly to the
        postgres command.
        -o can be specified multiple times, with all the given
        options being passed through.
       
        The options should usually be surrounded by single or
        double quotes to ensure that they are passed through as a group.
       
-o initdb-options--options=initdb-options
        Specifies options to be passed directly to the
        initdb command.
        -o can be specified multiple times, with all the given
        options being passed through.
       
        The initdb-options should usually be surrounded by single or
        double quotes to ensure that they are passed through as a group.
       
-p path
        Specifies the location of the postgres
        executable.  By default the postgres executable is taken from the same
        directory as pg_ctl, or failing that, the hard-wired
        installation directory.  It is not necessary to use this
        option unless you are doing something unusual and get errors
        that the postgres executable was not found.
       
        In init mode, this option analogously
        specifies the location of the initdb
        executable.
       
-s--silentPrint only errors, no informational messages.
-t seconds--timeout=seconds
        Specifies the maximum number of seconds to wait when waiting for an
        operation to complete (see option -w).  Defaults to
        the value of the PGCTLTIMEOUT environment variable or, if
        not set, to 60 seconds.
       
-V--versionPrint the pg_ctl version and exit.
-w--wait
        Wait for the operation to complete.  This is supported for the
        modes start, stop,
        restart, promote,
        and register, and is the default for those modes.
       
        When waiting, pg_ctl repeatedly checks the
        server's PID file, sleeping for a short amount
        of time between checks.  Startup is considered complete when
        the PID file indicates that the server is ready to
        accept connections.  Shutdown is considered complete when the server
        removes the PID file.
        pg_ctl returns an exit code based on the
        success of the startup or shutdown.
       
        If the operation does not complete within the timeout (see
        option -t), then pg_ctl exits with
        a nonzero exit status.  But note that the operation might continue in
        the background and eventually succeed.
       
-W--no-wait
        Do not wait for the operation to complete.  This is the opposite of
        the option -w.
       
If waiting is disabled, the requested action is triggered, but there is no feedback about its success. In that case, the server log file or an external monitoring system would have to be used to check the progress and success of the operation.
        In prior releases of PostgreSQL, this was the default except for
        the stop mode.
       
-?--helpShow help about pg_ctl command line arguments, and exit.
If an option is specified that is valid, but not relevant to the selected operating mode, pg_ctl ignores it.
-e source
       Name of the event source for pg_ctl to use
       for logging to the event log when running as a Windows service.  The
       default is PostgreSQL.  Note that this only controls
       messages sent from pg_ctl itself; once
       started, the server will use the event source specified
       by its event_source parameter.  Should the server
       fail very early in startup, before that parameter has been set,
       it might also log using the default event
       source name PostgreSQL.
      
-N servicename
       Name of the system service to register. This name will be used
       as both the service name and the display name.
       The default is PostgreSQL.
      
-P passwordPassword for the user to run the service as.
-S start-type
       Start type of the system service.  start-type can
       be auto, or demand, or
       the first letter of one of these two. If this option is omitted,
       auto is the default.
      
-U username
       User name for the user to run the service as. For domain users, use the
       format DOMAIN\username.
      
PGCTLTIMEOUTDefault limit on the number of seconds to wait when waiting for startup or shutdown to complete. If not set, the default is 60 seconds.
PGDATADefault data directory location.
   Most pg_ctl modes require knowing the data directory
   location; therefore, the -D option is required
   unless PGDATA is set.
  
   pg_ctl, like most other PostgreSQL
   utilities,
   also uses the environment variables supported by libpq
   (see Section 33.14).
  
For additional variables that affect the server, see postgres.
postmaster.pidpg_ctl examines this file in the data directory to determine whether the server is currently running.
postmaster.optsIf this file exists in the data directory,
      pg_ctl (in restart mode)
      will pass the contents of the file as options to
      postgres, unless overridden
      by the -o option. The contents of this file
      are also displayed in status mode.
     
To start the server, waiting until the server is accepting connections:
$pg_ctl start
    To start the server using port 5433, and
    running without fsync, use:
$pg_ctl -o "-F -p 5433" start
To stop the server, use:
$pg_ctl stop
    The -m option allows control over
    how the server shuts down:
$pg_ctl stop -m smart
    Restarting the server is almost equivalent to stopping the
    server and starting it again, except that by default,
    pg_ctl saves and reuses the command line options that
    were passed to the previously-running instance.  To restart
    the server using the same options as before, use:
$pg_ctl restart
    But if -o is specified, that replaces any previous options.
    To restart using port 5433, disabling fsync upon restart:
$pg_ctl -o "-F -p 5433" restart
Here is sample status output from pg_ctl:
$pg_ctl statuspg_ctl: server is running (PID: 13718) /usr/local/pgsql/bin/postgres "-D" "/usr/local/pgsql/data" "-p" "5433" "-B" "128"
The second line is the command that would be invoked in restart mode.