Rtfm

Cela peut par exemple vous servir pour gérer ou retrouver vos tunnel.

Extrait du man :

 ESCAPE CHARACTERS
     When a pseudo-terminal has been requested, ssh supports a number of func-
     tions through the use of an escape character.

     A single tilde character can be sent as ~~ or by following the tilde by a
     character other than those described below.  The escape character must
     always follow a newline to be interpreted as special.  The escape charac-
     ter can be changed in configuration files using the EscapeChar configura-
     tion directive or on the command line by the -e option.

     The supported escapes (assuming the default `~') are:

     ~.      Disconnect.

     ~^Z     Background ssh.

     ~#      List forwarded connections.

     ~&      Background ssh at logout when waiting for forwarded connection /
             X11 sessions to terminate.

     ~?      Display a list of escape characters.

     ~B      Send a BREAK to the remote system (only useful for SSH protocol
             version 2 and if the peer supports it).

     ~C      Open command line.  Currently this allows the addition of port
             forwardings using the -L, -R and -D options (see above).  It also
             allows the cancellation of existing port-forwardings with
             -KL[<em>bind_address</em>:]<em>port</em> for local, -KR[<em>bind_address</em>:]<em>port</em> for re-
             mote and -KD[<em>bind_address</em>:]<em>port</em> for dynamic port-forwardings.
             !<em>command</em> allows the user to execute a local command if the
             PermitLocalCommand option is enabled in <a href="http://man.openbsd.org/">ssh_config(5)</a>.  Basic
             help is available, using the -h option.

     ~R      Request rekeying of the connection (only useful for SSH protocol
             version 2 and if the peer supports it).

man rtfm

NAME

   rtfm - a response for easy questions from clueless lusers

SYNOPSIS

   rtfm [ -p ] [ -h ] [ -d option ] [ -i interval ] [ -a action ] [ -q
   luser]

DESCRIPTION

   rtfm is a command for system administrators to use in dealing with new
   users. rtfm is useful for dealing with users having trouble with their
   pictures downloaded from alt.binaries.pictures.erotica. rtfm will
   continue to run until killed by hand, using `kill processid'. rtfm can
   be invoked by anyone who has enough of a clue to know what a man page
   is.

OPTIONS

   -p
          Give the answer in a polite fashion.
   -h
          Tell the clueless luser to go to hell. Used with the -p option,
          they'll look forward to the trip.
   -d option
          Debug mode using option where option is one of the following:
          query Ask the luser what part of rtfm that he or she does not
          understand.
          planet Ask what planet the luser is from.
          literacy Ask the luser if the luser can read.
          english Ask the luser if the luser understands English.
          Mac Ask the luser if the luser has ever used a computer other
          than a Macintosh.
          Nintendo Same as the Mac option, but slightly more harsh.
   -i interval
          Enable within interval seconds. interval is the time between a
          luser asking the same damn fool question. This option must be
          activated for the -a option. It stores the time of the question
          in /var/run/luser and checks that file each time that rtfm is
          activated. interval is a number of minutes, of the form xxx.xx
          where each x is a decimal digit. The default is 5.00 minutes.
   -a action
          This defines some action to be taken in the event that the -i
          flag condition is met. action can be defined either at the flag
          level or by a file. The options for flags are as follows:
          scream Let out a scream of utter frustration.
          hair Rip out your hair in total frustration.
          rm Automatic command ran in lusers home directory. It can have
          an addition -rf flag added.
          ignore Ignore the luser.
          warn Warn the other sysadmins.
          forward Forward to CNS advising. Particularly if the complaint
          is /dev/null is full.
          kill Kill all the lusers processes.
          FILE=file.name Use a file to define a course of actions. This
          can be any executable file except those using ksh, which no
          god-fearing right-thinking sysadmin would be caught using lest
          he be struck down by the wrath of God.
   -q luser
          Query file /etc/luser to see if luser is a real luser or a
          first time luser.

FILES

   /etc/luser

SEE ALSO

   mr.biff(2),

BUGS

   rtfm only checks /var/run/luser when the -a option is specified and
   after the -i option is invoked. Otherwise /tmp would fill up rapidly
   on many systems. Also, core may dump if the -a FILE= option is
   anatomically impossible.```