.\" -*- nroff -*-
.TH MODEMU 1 "1 April 1995" "Version 0.0"
.\"
.\"
.SH NAME
.\"
modemu \- dialup TCP connecting
.\"
.\"
.SH SYNOPSIS
.\"
.B modemu
[\fB-c \fIcomm_prog\fR] [\fB-d \fIpty_master\fR] [\fB-e \fIatcmds\fR]
[\fB-h\fR] [\fB-s\fR] [\fB-\fR]
.\"
.\"
.SH DESCRIPTION
.\"
.B Modemu
is a TELNET client with a modem-like user interface.
It can redirect its I/O via a
.BR pty (4)
so that a comm program can handle the pty as a tty with a real modem.
.PP
.B Modemu
has two major modes: a command mode and online mode.
When invoked,
.B modemu
is in the command mode, waiting for AT commands input.
Entering a D or O command will put into the online mode, in which \" <===
.B modemu
communicate with a remote host.
Connection closing or a escape command input returns to the command mode.
.\"
.\"
.SH OPTIONS
.\" ===== -c =====
.TP
.BI -c " comm_prog"
Invoke a comm program \fIcomm_prog\fP.
.B Modemu
invokes it by passing /bin/sh an option `-c \fIcomm_prog\fP'.
Therefore, any
.BR sh (1)
commands can be specified.
The string \fIcomm_prog\fP can include a `%s',
which will be replaced with the 
device name of the slave device after removal of the initial "/dev/".
.RS
Example:
.RS
modemu -c "xc -l %s"
.RE
.RE
.\" ===== -d =====
.TP
.BI -d " pty_master"
Open a file \fIpty_master\fP and talk through it.
A named pipe can be a
.I pty_master
as well as a pty master device because
.B modemu
doesn't ioctl a \fIpty_master\fP.
.\" ===== -e =====
.TP
.BI -e " atcmds"
Execute a series of AT commands \fIatcmds\fP initially.
.I Atcmds
must have an `AT' or `at' prefix.
D and O commands in \fIatcmds\fP are ignored.
.\" ===== -h =====
.TP
.B -h
Print a usage summary.
.\" ===== -s =====
.TP
.B -s
Print the last two letters of a device name.
The device is a pty master device which
.B modemu
talks through.
Therefore, when
.B modemu
prints `p8',
comm program must open /dev/tty\fIp8\fP.
.\" ===== - =====
.TP
.B `-'
.B Modemu
talks through the standard input/output. (Default)
.\" ==========
.PP
Note: -c, -d, -s and - options are exclusive each other.
If two or more of the options are specified,
only the last one is effective.
.\"
.\"
.SH COMMAND MODE
.\"
Command mode expects lines in the following format:
.IP ""
[\fIgarbage\fP]\fIat\fP[\fIsp\fP][\fIcmd\fP[\fIsp\fP]]...\fIcr\fP
.PP
where
.I at
is an `AT' or `at',
.I sp
is spaces,
.I cr
is a carriage return character (register S3),
.I garbage
is a string includes no \fIat\fP.
If a `#' prefixes a line, the line is ignored.
Available
.IR cmd s
are listed below.
They are all case in-sensitive except for some literally used arguments.
A (*) marks default settings.
.\" ===== D =====
.TP
.BI D str
Dialing command.
Open a connection to \fIhost\fP.
If \fIport\fP is specified,
.B modemu
attempts to connect with the port instead of the default TELNET port,
and
doesn't initiate TELNET option negotiation.
The following formats are available for \fIstr\fP:
.RS
.TP
\fIhost\fP[:\fIport\fP]
\fIHost\fP is an Internet address in numbers-and-dots notation.
Optional \fIport\fP is a port number.
.TP
"\fIhost\fP[:\fIport\fP]["]
\fIHost\fP is an Internet address or host name.
Optional \fIport\fP is a port number or service name.
The closing double quote can be omitted if no command follows.
.PP
.I Str
can be prefixed with `T', `P', `\fIdigit\fPW' and/or `\fIdigit\fP,'.
The prefixes are simply ignored.
.br
Example:
.RS
ATDT0W127.0.0.1
.br
ATDP"foo.bar.jp:daytime
.RE
.RE
.\" ===== E =====
.TP
.B E1
No operation.
.\" ===== F =====
.TP
.B F1
No operation.
.\" ===== H =====
.TP
.BR H [ 0 ]
Close the current TELNET session.
.\" ===== I =====
.TP
.BI I n
Print various information.
.RS
.IP I4
Current settings
.IP I5
`&W'ed settings
.IP I6
TELNET option states
.IP I7
.B Modemu
version
.RE
.\" ===== O =====
.TP
.BR O [ 0 ]
Return to online mode.
.\" ===== P =====
.TP
.B P
No operation.
.\" ===== Q =====
.TP
.BR Q [ 0 ]
No operation.
.TP
.B T
No operation.
.\" ===== V =====
.TP
.B V1
No operation.
.\" ===== X =====
.TP
.BR X [ 0 ]
No operation.
.\" ===== Sn=m =====
.TP
.BI S n = m
Set S-register S\fIn\fP to \fIm\fP.
A number from 0-255 is allowed for \fIm\fP.
.\" ===== Sn? =====
.TP
.BI S n ?
Print an S-register S\fIn\fP's value.
.\" ===== Z =====
.TP
.B Z
Close the current TELNET session, and restore `&W'ed settings.
.\" ===== &W =====
.TP
.B &W
Save current settings.
The saved settings will be lost with the end of the process
because they are not stored into NV-RAM nor files.
.\" ===== %B =====
.TP
.BI %B n = m
Control TELNET binary option.
Valid values for \fIn\fP are:
.RS
.RS
.IP 0
Control the local (modemu) option
.IP 1
Control the remote (TELNET server) option
.RE
.PP
Valid values for \fIm\fP are:
.RS
.IP 0
Request non-binary transmission mode (*)
.IP 1
Request binary transmission (8bit through) mode
.TP
.I above+2
Disconnect if the request is refused
.RE
.PP
Example:
.RS
.IP AT%B1=1
Requesting binary mode in remote-to-modemu direction
.IP AT%B0=3%B1=3
Requesting binary mode
in both remote-to-modemu and modemu-to-remote direction.
No use connecting in non-binary mode (using file xfer protocol or something)
.RE
.RE
.\" ===== %D =====
.TP
.BI %D n
Control dial-canceling.
.RS
.IP %D0
A keypress cancels dialing (*)
.IP %D1
Keypresses don't cancel dialing
.RE
.\" ===== %L =====
.TP
.BI %L n
Control line-mode.
.RS
.IP %L0
Request character-at-a-time mode (*)
.IP %L1
Request line-at-a-time mode (old line-mode).
Input characters are buffered and not sent until a CR character is entered.
.RE
.\" ===== %Q =====
.TP
.B %Q
Quit
.BR modemu .
.\" ===== %R =====
.TP
.BI %R n
Control raw-mode.
.RS
.IP %R0
Normal mode (*)
.IP %R1
Raw mode.
.B Modemu
transmits every octet as received.
Applied to both remote-to-modemu and modemu-to-remote direction.
Override %B and %L settings.
.RE
.\" ===== %T =====
.TP
.BI %T str
Control TELNET terminal-type option.
.RS
.IP %T0
Refuse terminal-type option
.IP %T1
Same as %T="$\fBTERM\fP"
(\fBTERM\fP environment value is used) (*)
.IP %T="\fIterm\fP["]
Send \fIterm\fP as the terminal-type if remote requests.
The closing double quote can be omitted if no command follows.
.RE
.\" ===== %V =====
.TP
.BI %V n
Control verbose level.
%V0 (*) is the quietest, and adding following values to \fIn\fP lets
.B modemu
print more information to stderr.
.RS
.IP +1
Print misc info to make up for less descriptive ATX0 indication
.IP +2
Print TELNET option negotioation
.RE
.\"
.\"
.SH ONLINE MODE
.\"
.B Modemu
recognizes only the following command when in online mode.
.\" ===== +++ =====
.TP
.IB "wait " +++ " wait"
Escape to command mode.
The `+++' must be input within the guard time.
.I Wait
is a period of time longer than the guard time
without hitting any key.
See also S2 and S12 register descriptions.
.\"
.\"
.SH S REGISTERS
.\"
Only meaningful registers are listed here.
Values in braces are default ones.
.TP
.B S2
Escape character code. (43 = `+')
.TP
.B S3
Carriage return character code.
(13)
.TP
.B S4
Line feed character code.
(10)
.TP
.B S5
Backspace character code.
(8)
.TP
.B S7
Connecting attempt time limit in seconds.
(20)
.TP
.B S12
Escape sequence guard time in 50ths of a second. 
(50)
.\"
.\"
.SH ENVIRONMENT VARIABLES
.\"
.TP
.B MODEMU
Initially evaluated as AT commands
(before -e option argument is evaluated).
Must have an `AT' or `at' prefix.
.TP
.B TERM
See %T1 command description.
.\"
.\"
.SH AUTHOR
Toru Egashira (egashira@nwk.CL.nec.co.jp)
.\"
.\"
.SH SEE ALSO
telnet(1),
.I Your favorite modem's manual
.\"
.\"
.SH BUGS
.\"
No dial-resriction, or blacklisting, capability.
So using
.B modemu
maybe unlawful in some countries. B)