JERM(1)                                     BSD General Commands Manual                                     JERM(1)

NAME
     jerm — communication terminal through serial and TCP/IP interfaces

SYNOPSIS
     jerm [-common_options] [-device_options] [-client_options] device_file
     jerm [-46] [-P port] [-common_options] [-client_options] host_name
     jerm -i [-46] [-P port] [-common_options] [-device_options] [-client_options] host_name < device_file >
          device_file
     jerm -D [-46T] [-P port] [-common_options] device_file

DESCRIPTION
     jerm is primarily intended to communicate with a remote machine through a serial interface.  Additionally jerm
     can communicate with another through a TCP/IP connection like telnet(1) and relay a serial communication to a
     TCP/IP connection to another remote machine.

     To connect a remote machine through a serial interface, use the first form.  device_file should be a special
     device file of a serial interface (typically /dev/cu*).  The second form lets jerm connect to the remote ma‐
     chine host_name through the TCP port.  In the case of invoking jerm with the third or the fourth form, it re‐
     lays the communications between a serial and a TCP/IP ports.  The former relays the specific machine host_name
     and the serial device_file, while the latter lets jerm work as a daemon; it listens to the TCP port first.
     After a connection on the port is established, then jerm opens the device device_file and relay the communica‐
     tions between the TCP port and the device.  See EXAMPLES for more information.

     The following options are available:

   Common options
     -z      Empty the log file at first.

     -l log_file
             Write output characters to log_file.  Since jerm always appends characters to log_file, use -z in con‐
             junction with this flag to log a single session.

   Device options
     -b speed
             Designate the speed of serial interface. The default is 9600.

     -p n[one]|e[ven]|o[dd]
             Designate the parity of serial interface.  The valid value is one of ‘none’, ‘even’ or ‘odd’.  The
             first character is suffice.  The default is ‘none’.

     -d 7|8  Designate the bit length of data.  The default is ‘8’.

     -s 1|1.5|2
             Designate the stop bit.  The default is ‘1’.

     -f n[one]|x|h[ard]
             Designate the flow control.  The default is ‘none’.

   Client options
     -x    Starts in hexadecimal dump mode.

     -r rnRN
           Set CR NL mapping method.  Option argument rnRN consists of four charactears.  Each character may be the
           one of the followings:
                 `x' Map to nothing. (drop)
                 `r' Map to CR.
                 `n' Map to NL.
                 `t' Map to CR+NL.
           The argument r specifies how to map a CR from remote to local, n specifies how to map a NL from remote
           to local, R specifies how to map a CR from local to remote, and N specifies how to map a NL from local
           to remote.  The default is ‘rnrn’.

   Other options
     -i    Pipe mode.  Initialize the standard input/output as a serial interface.

     -4    Use IPv4 for TCP/IP connection.

     -6    Use IPv6 for TCP/IP connection.

     -P port
           Designate TCP port for TCP/IP connection. The default port is ‘8086’.

     -T    Use hosts_access(3) when accepting connection.

   Escape Characters
     Typed characters are normally transmitted directly to the remote machine (which does the echoing as well).  A
     tilde preceded by a Control-M or Enter (‘^M ~’) is an escape signal; the following are recognized:

     ^M ~ .
           Drop the connection and exit (you may still be logged in on the remote machine).  When jerm is invoked
           as a relaying server (with -D), Control-C (‘^C’) will terminate jerm.  If in the pipe mode (-i is
           specified), jerm does not terminate.  Send a hang up signal (typically kill -HUP) instead.

     ^M ~ ~
           Send a tilde (‘~’) to the remote machine.

     ^M ~ #
           Send a BREAK signal to the remote machine.

     ^M ~ > file
           Send the local file file to the remote machine as its input.

     ^M ~ x
           Toggle back and forth between the normal and the hexadecimal dump mode. The hexadecimal dump mode dis‐
           plays received characters in hexadecimal.

     ^M ~ r rnRN
           Set CR NL mapping method in the same manner as the -r option.

     ^M ~ ?
           Get a summary of the ‘^M ~’ escapes.

EXAMPLES
     The command:
           jerm /dev/cuaa0 (FreeBSD)
           jerm /dev/dty00 (NetBSD)
           jerm /dev/cua00 (OpenBSD)
           jerm /dev/cu.usbmodemUSB-COM (Darwin/Mac OS X)
     connects a remote host through a serial interface.  The actual device file may vary.

     When FreeBSD HOST1 connects to the remote machine RMACH through a serial interface, The command:
           jerm -D -P 9800 -b 4800 /dev/cuaa0
     on HOST1 will relay RMACH to TCP port 9800.  Then the command:
           jerm -P 9800 HOST1
     on NetBSD HOST2 can communicate with RMACH.  Instead of the above command, execute the command:
           jerm -i -P 9800 HOST1 -b 4800 < /dev/dty00 > /dev/dty00
     on the HOST2 and connect HOST2's serial interface with Darwin HOST3, then the command:
           jerm /dev/cu.usbmodemUSB-COM
     on HOST3 connects RMACH through HOST1 and HOST2.

SEE ALSO
     cu(1), tip(1), telnet(1)

AUTHOR
     KANDA Toshihiro

BUGS
     Although jerm with TCP/IP connection is analogous to telnet(1), jerm does not support telnet protocol.

BSD                                                 Jul 16, 2004                                                BSD