.TH EXPECT 1
.SH NAME
at, drain, expect, pass \- dialer scripting tools
.SH SYNOPSIS
.B dial/at
[
.B -q
] [
.B -t
.I seconds
]
atcommand
.br
.B dial/expect
[
.B -iq
] [
.B -t
.I seconds
]
.I goodstring
[
.IR badstring ...
]
.br
.B dial/drain
.br
.B dial/pass
[
.B -q
]
.SH DESCRIPTION
These commands are used to write telephone dialing
scripts, mostly for PPP sessions.  They all expect standard input and
output to be connected to a communications device, e.g,
a serial line to a modem.  They communicate with the user using
.BR /dev/cons .
.PP
.I At
sends
.B atcommand
to the modem prefixed with the string
.BR at .
It then reads from the modem expecting an AT response. 
.I At
will return success if it gets and
.B OK
of
.B CONNECT
response.  Otherwise it will return the response as an
error status.  The options are:
.TP
.B -t
set the timeout to
.IR seconds .
The default is 300.
.TP
.B -q
don't write to
.B /dev/cons
what is read from standard in.  The default is
to copy everything through.
.PD
.PP
.I Expect
reads standard input looking for one of the strings given
as arguments.  Reading the first string causes a successul exit
status.  Reading any of the others causes an exit status equal to
the string.  The command also terminates on a timeout.  The options
are:
.TP
.B -t
set the timeout to
.IR seconds .
The default is 300.
.TP
.B -i
ignore case when doing the matches.
.TP
.B -q
don't write to
.B /dev/cons
what is read from standard in.  The default is
to copy everything through.
.PD
.PP
.I Pass
copies input from
.B /dev/cons
to standard output.
It terminates on a newline.  The only flag is
.B -q
and means the same as it does for
.IR expect .
.PP
.I Drain
discards any input waiting on standard input.  It
is used to sync up the stream at the start of dialing
or after an error.
.SH EXAMPLE
The following
.B rc
script dials out through a Hayes compatible modem on
.B /dev/eia1
and lets the user type in a user name and password
before starting
.BR ppp .
.EX
#!/bin/rc
dev=/dev/eia1
telno=18005551212

fn initfn {
	dial/drain
	echo +++
	dial/at zh0
}

fn dialfn {
	dial/drain
	dial/at dt^$telno
}
{
	# set up uart
	if( test -e $dev^ctl ){
		echo -n b^$baud
		echo -n m1	# cts/rts flow control
		echo -n q64000	# big buffer
		echo -n n1	# nonblocking writes
		echo -n r1	# rts on
		echo -n d1	# dtr on
		echo -n c1	# handup when we lose dcd
	} > $dev^ctl

	# get the modem's attention
	while( ! initfn )
		sleep 1

	# dial
	while( ! dialfn )
		sleep 30
		
	if( ! dial/expect -it 60 'username:' ){
		echo can''t connect >[1=2]
		exit connect
	}
	dial/pass
	if( ! dial/expect -it 60 'password:' ){
		echo can''t connect >[1=2]
		exit connect
	}
	dial/pass
	if( ! dial/expect -t 60 'ppp or telnet:' ){
		echo can''t connect >[1=2]
		exit connect
	}
	echo ppp
	dial/expect -t 5 something
	echo connected >[1=2]

	# start ppp
	ip/ppp $primary -f
} < $dev > $dev
.EE
.SH FILES
.B /rc/bin/ipconf/*
example dialer scripts for ppp
.SH SOURCE
.B /sys/src/cmd/dial/*.c
.SH SEE ALSO
.IR ppp (8),
.IR telco (4)