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REXEC(1)                                                              REXEC(1)



NAME
       rexec -- remote execution client for an exec server

SYNOPSIS
       rexec [ -abcdhns -l username -p password ] host command

DESCRIPTION
       Rexec calls the rexec(3) routine to act as a client for the remote host's rexecd(8) server.

       It  asks that ''command'' be run on the host computer, using username/password authentication. See rexec(3) and
       rexecd(8) for details of the protocol.

OPTIONS
       Rexec accepts several options, but only three are likely to be very useful:

       -l username

              Set the log-in name on the remote host to username.

       -p password

              Provide the password for the remote account.  The command line argument  will  be  blanked  after  being
              parsed,  to  prevent  it  from  being seen with ps(1).  However, it is still not very secure to type the
              password on the command line.  In particular, be sure that the shell's history file is protected.

       -n     Explicitly prompt for name and password, even if provided in the environment, in the $HOME/.netrc  file,
              or in the environmental variables REXEC_USER and REXEC_PASS.

       Other options that might be useful with non-standard remote exec daemons, or to debug connections:

       -a     Do not set up an auxiliary channel for standard error from command; the remote standard error and output
              are then both returned on the local standard output.  By default, rexec asks that a separate channel  be
              set up for diagnostic output from the remote command.

       -b     Use  signal  handling as in BSD rsh(1).  Only the signals SIGINT, SIGQUIT, and SIGTERM are echoed to the
              remote process.  They do not remain raised locally, so rexec waits for the remote  command  to  shutdown
              its  side of the socket.  Also, CNTRL-Z will only suspend execution locally--the remote command may con-
              tinue to run.

       -c     Do not close remote standard input when local standard input closes.  Normally the standard input to the
              remote command is closed when the local standard input is closed.

       -d     Turn on debugging information. In particular the command sent to the remote host will be echoed.

       -h     Print a usage message.

       -s     Do  not  echo  signals  received  by  the rexec onto the remote process.  Normally, signals which can be
              trapped are passed on to the remote process; then, when you type CNTRL-C, the remote process  terminates
              as well.

USERNAME AND PASSWORD
       Rexec(1) searches for the username and password in the following order:

              1.  If -n is given on the command line, the user will always be prompted for both, even if they are also
              given on the command line.

              2. The command line will be parsed

              3. If the environmental variables REXEC_USER or REXEC_PASS are defined, they will define the username or
              password.

              4. The $HOME/.netrc file will be searched.  See ftp(1) for a description of this file's format.

              5. Finally, the user will be prompted if either the username or password remains undefined.


SECURITY
       Users of this command should be aware that rexec(3) transmits their password to the remote host clear text, not
       encrypted.  If the network is not secure to the remote host, the password can be comprimised.


SIGNALS
       Without the -b option, all signals which can be handled are echoed to the remote process.  Afterwards, however,
       they remain raised in the local process.  Typically, this means that rexec(1) will exit after receiving a fatal
       signal, even if the remote process has arranged to handle or ignore it.

       Differing operating systems use differing signal numbers; for example AIX and SunOS use 18  for  SIGTSTP  (^Z),
       while  Linux  uses 20.  Therefore, it may have a different effect remotely than locally.  In particular, typing
       CNTL-Z may not suspend the execution of the remote process.

EXAMPLE
       rexec othermachine cat ">remote_file; date" <local_file

       will send local_file to the othermachine as remote_file.


BUGS
       Please send bug reports, system incompatibilities, and job offers to the author.

SEE ALSO
       rexec(3), rexecd(8), rsh(1)

AUTHOR
       Michael Sadd
       mas22ATcornell.edu
       http://www.tc.cornell.edu/~sadd/

       Thanks to Orange Gopher (2/10/97) and Johannes Plass (plassATdipmza.de, Oct. 17 1996) for  use-
       ful suggestions.



                               February 14, 1997                      REXEC(1)