EXPECT(1)EXPECT(1)

NAME

at, drain, expect, pass – dialer scripting tools

SYNOPSIS

dial/at [ -q ] [ -t seconds ] atcommand
dial/expect [ -iq ] [ -t seconds ] goodstring [ badstring... ]
dial/drain
dial/pass [ -q ]

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 /dev/cons.

At sends atcommand to the modem prefixed with the string at. It then reads from the modem expecting an AT response. At will return success if it gets and OK of CONNECT response. Otherwise it will return the response as an error status. The options are:

-t

set the timeout to seconds. The default is 300.  

-q

don’t write to /dev/cons what is read from standard in. The default is to copy everything through.  

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:

-t

set the timeout to seconds. The default is 300.  

-i

ignore case when doing the matches.  

-q

don’t write to /dev/cons what is read from standard in. The default is to copy everything through.  

Pass copies input from /dev/cons to standard output. It terminates on a newline. The only flag is -q and means the same as it does for expect.

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.

EXAMPLE

The following rc script dials out through a Hayes compatible modem on /dev/eia1 and lets the user type in a user name and password before starting ppp. 

#!/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

FILES

/rc/bin/ipconf/* example dialer scripts for ppp

SOURCE

/sys/src/cmd/dial/*.c

SEE

ppp(8), telco(4)