Wifiweasel

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Line 1: Line 1:
script to Auto connect to Open 802.11 wireless AP's
+
{{Todo|Dear maintainer: Please add an introduction to this article.}}
 +
 
 +
[[image:Weaselwifi.jpg|right|220px]]
 +
 
 +
see also [[Lint-wifi]]
 +
 +
== wpa_config auto connect any ==
 +
<PRE>
 +
root@om-gta02:~# cat ./wifiupp
 +
killall udhcpc
 +
wpa_supplicant -ieth0 -c/etc/wpa_supplicant/wpa_supplicant.conf -B
 +
udhcpc
 +
 
 +
 
 +
 
 +
root@om-gta02:~# cat /etc/wpa_supplicant/wpa_supplicant.conf
 +
 
 +
ctrl_interface=/var/run/wpa_supplicant
 +
ctrl_interface_group=0
 +
eapol_version=1
 +
ap_scan=1
 +
fast_reauth=1
 +
 
 +
network={
 +
        key_mgmt=NONE
 +
        priority=-9999999
 +
}
 +
 
 +
 
 +
root@om-gta02:~#
 +
 
 +
root@om-gta02:~# cat  /usr/share/applications/wifiupp.desktop
 +
[Desktop Entry]
 +
Name=wifiup
 +
Comment=wpa_supplicant start
 +
Encoding=UTF-8
 +
Version=1.0
 +
Type=Application
 +
Exec=/home/root/wifiupp &
 +
Icon=fixmeh
 +
Terminal=true
 +
SingleInstance=true
 +
StartupNotify=true
 +
root@om-gta02:~#
 +
 
 +
 
 +
 
 +
</PRE>
 +
 
 +
=FAIL=
 +
 
 +
script to Auto connect to Open 802.11 wireless AP's ***DOESNT WORK*** i think something is wrong with the driver and it doesnt reset properly with this procedure, anyone else test re-associating with separate aps manually?
 +
 
 
====wifiweasel====
 
====wifiweasel====
 
wifiweasel v2 -  
 
wifiweasel v2 -  
Line 7: Line 59:
 
whole process repeats itself; this requires the timeout script below  
 
whole process repeats itself; this requires the timeout script below  
  
 +
[ [ comment: Func_MAIN calls Func_chk_net calls Func_Main(!!)... calls... (BUG?) ] ]
 
<pre>  
 
<pre>  
 
#!/bin/sh
 
#!/bin/sh
Line 48: Line 101:
 
#### iface up Funk
 
#### iface up Funk
 
Func_ifconfig_up () {
 
Func_ifconfig_up () {
 +
ifconfig $IFACE up
 
iwconfig $IFACE essid `cat $TEMPDIR/ESSID`  
 
iwconfig $IFACE essid `cat $TEMPDIR/ESSID`  
 
}
 
}
Line 55: Line 109:
 
export dns=`cat /etc/resolv.conf |grep name |awk '{print $2}'`
 
export dns=`cat /etc/resolv.conf |grep name |awk '{print $2}'`
 
timeout 1 nslookup  $dns  
 
timeout 1 nslookup  $dns  
if [ $=0 ];then ERROR=0; echo; echo Online!  W00T ; echo ;echo using essid ; cat $TEMPDIR/ESSID ; sleep $CHECK_NET_TIMER ; Func_chk_net ;  
+
if [ $? = 0 ];then ERROR=0; echo; echo Online!  W00T ; echo ;echo using essid ; cat $TEMPDIR/ESSID ; sleep $CHECK_NET_TIMER ; Func_chk_net ;  
 
fi  #W00T
 
fi  #W00T
if [ $=143 ] ; then ERROR=1 ;echo ;echo FAIL!\  
+
if [ $? -ge 1] ; then ERROR=1 ;echo ;echo FAIL!\  
 
... Searching ; echo ; Func_Main ;
 
... Searching ; echo ; Func_Main ;
 
fi  
 
fi  
Line 150: Line 204:
 
not sure but i think one has to make the /tmp/ files manually
 
not sure but i think one has to make the /tmp/ files manually
 
*fixed as of v2
 
*fixed as of v2
 +
 +
= Am Improved Version Of wifiweasel =
 +
 +
Looking carefully through the code there seemed to be logical errors in the control structure of the program. This version is supposed to be logically similar without the recursive function calls. I have made very limited use of it but am submitting it here in case its useful for others. I call it wifiweasel3.sh It also uses environment variables instead of temporary files, which may or may not be a good thing.
 +
 +
1) Copy it to your phone,
 +
2) chmod +x wifiweasel3.sh
 +
3) ensure that you have the timeout program above copied and executable.
 +
4) Run it - At first you can try
 +
  wifiweaselv3.sh -v
 +
  which gives you a verbose account of what is happening.
 +
  you can also do
 +
  wifiweasel start
 +
  and wifiweasel stop
 +
 
 +
  which keeps it silently backgrounded.
 +
 +
Here is the code:
 +
 +
<pre>#!/bin/sh
 +
####### WifiWeasel ######
 +
# Ver. 2              ##
 +
#########################
 +
# 08-07-22            ##
 +
##        kd8ikt      ##
 +
##  we.trekbeyond.org  ##
 +
#########################
 +
# Ver 3 Mark Winder 27/7/8
 +
#########################
 +
#
 +
#install /usr/bin/wifiweasel
 +
#
 +
#Variables
 +
IFACE=eth0
 +
DHCP_TIMEOUT=5      # requires /usr/bin/timeout
 +
CHECK_NET_TIMER=15  #secs
 +
# call -v for debug to std out
 +
PIDFILE=/tmp/wifiweasel.pid
 +
[[ "$1" == '-v' ]] && debug=1 && shift
 +
if [[ "$1" == 'start' ]]
 +
then
 +
  shift
 +
  wifiweasel3.sh "$@" &
 +
  echo $! > $PIDFILE
 +
  exit
 +
fi
 +
if [[ "$1" == 'stop' ]]
 +
then
 +
  if [[ -e $PIDFILE ]]
 +
  then
 +
    kill $(cat $PIDFILE)
 +
    rm $PIDFILE
 +
    echo "WiFiWeasel stopped";
 +
  fi
 +
  exit
 +
fi
 +
 +
#
 +
#Functions
 +
#
 +
#### Scan Funk
 +
Func_iwlist_open ()
 +
{
 +
  ESSID=$(iwlist $IFACE scanning |
 +
      awk -F '[ :=]+' '/(ESS|Freq|Qual)/{ printf $3" " } /Encr/{ print $4 }'  |
 +
      sort -k4 -k3nr |grep off |
 +
      head -n1| sed 's/^"//;s/".*$//'
 +
    )
 +
  [[ $debug ]] && echo Using ESSID $ESSID
 +
}
 +
#### interface down Funk
 +
Func_ifconfig_down ()
 +
{
 +
  killall udhcpc
 +
  ifconfig $IFACE down
 +
}
 +
#### iface up Funk
 +
Func_ifconfig_up ()
 +
{
 +
  ifconfig $IFACE up
 +
  iwconfig $IFACE essid $ESSID
 +
}
 +
#### Connection check Funk
 +
#
 +
Func_net_ok ()
 +
{
 +
  [[ $debug ]] && echo checking... 
 +
  export dns=`cat /etc/resolv.conf |grep name |awk '{print $2}'`
 +
  if timeout 1 nslookup  $dns > /dev/null 2>&1
 +
  then
 +
    [[ $debug ]] && echo Online!  $ESSID
 +
    return 0 # net is ok
 +
  else
 +
    [[ $debug ]] && echo "FAIL! $?  ... Searching "
 +
    return 1 # net not ok
 +
  fi
 +
}
 +
# RunProgram
 +
while [[ 1 ]]
 +
do
 +
  if [[ -z $ESSID ]] # no essid ?
 +
  then
 +
    Func_ifconfig_down
 +
    Func_iwlist_open
 +
    Func_ifconfig_up
 +
    timeout $DHCP_TIMEOUT udhcpc $IFACE > /dev/null 2>&1
 +
  fi
 +
  sleep $CHECK_NET_TIMER
 +
  Func_net_ok || ESSID=""
 +
done
 +
#####################EOF#EOF#EOF#EOF#EOF#EOF#EOF#EOF#EOF#########
 +
 +
 +
</pre>
  
 
=sandbox=
 
=sandbox=
Line 194: Line 362:
 
<br> "ESSID_NAME2" 1 -49 off
 
<br> "ESSID_NAME2" 1 -49 off
  
[[category:Technical ]]
+
[[Category:Wlan software]]
[[category:GTA02 Hardware]]
+
[[Category:Neo FreeRunner Hardware]]

Latest revision as of 15:36, 10 July 2009

TODO: Dear maintainer: Please add an introduction to this article. (See: To-Do List)
Weaselwifi.jpg

see also Lint-wifi

Contents

[edit] wpa_config auto connect any

root@om-gta02:~# cat ./wifiupp 
killall udhcpc
wpa_supplicant -ieth0 -c/etc/wpa_supplicant/wpa_supplicant.conf -B
udhcpc



root@om-gta02:~# cat /etc/wpa_supplicant/wpa_supplicant.conf 

ctrl_interface=/var/run/wpa_supplicant
ctrl_interface_group=0
eapol_version=1
ap_scan=1
fast_reauth=1 

network={
         key_mgmt=NONE
         priority=-9999999
}


root@om-gta02:~# 

root@om-gta02:~# cat  /usr/share/applications/wifiupp.desktop 
[Desktop Entry]
Name=wifiup
Comment=wpa_supplicant start
Encoding=UTF-8
Version=1.0
Type=Application
Exec=/home/root/wifiupp &
Icon=fixmeh
Terminal=true
SingleInstance=true
StartupNotify=true
root@om-gta02:~# 



[edit] FAIL

script to Auto connect to Open 802.11 wireless AP's ***DOESNT WORK*** i think something is wrong with the driver and it doesnt reset properly with this procedure, anyone else test re-associating with separate aps manually?

[edit] wifiweasel

wifiweasel v2 - once run this script takes control of the wireless interface, then detects and connects to strongest open wifi AP in the vicinity. Subsequently it checks the connectivity every X seconds. If the connection fails, the whole process repeats itself; this requires the timeout script below

[ [ comment: Func_MAIN calls Func_chk_net calls Func_Main(!!)... calls... (BUG?) ] ]

 
#!/bin/sh
####### WifiWeasel ###### Ver. 2
######################### 08-07-22
##        kd8ikt       ##
##  we.trekbeyond.org  ##
#########################
#########################
#
#install /usr/bin/wifiweasel
#
#Variables
IFACE=eth0
DHCP_TIMEOUT=5       # requires /usr/bin/timeout
CHECK_NET_TIMER=15   #secs
TEMPDIR=/tmp/wifiweasel/
#
#Functions
#
#(dont touch unless you 
#know wtf your doing
#
#### Scan Funk
Func_iwlist_open () {
iwlist $IFACE scanning | awk -F '[ :=]+' '/(ESS|Freq|Qual)/{ printf $3" " } /Encr/{ print $4 }' \
    | sort -k4 -k3nr |grep -m1 off \
|awk '{print $1}' > /tmp/wifiweasel/scan
cat $TEMPDIR/scan |grep '"' -m1 > $TEMPDIR/scan1
sed /\"/s/\"//g $TEMPDIR/scan1 > $TEMPDIR/ESSID
echo 
echo Using ESSID
cat $TEMPDIR/ESSID
echo
}
#### interface down Funk
Func_ifconfig_down () {
killall udhcpc 
ifconfig $IFACE down
}
#### iface up Funk
Func_ifconfig_up () {
ifconfig $IFACE up
iwconfig $IFACE essid `cat $TEMPDIR/ESSID` 
}
#### Connection check Funk
Func_chk_net ()	{
echo checking...   
export dns=`cat /etc/resolv.conf |grep name |awk '{print $2}'`
timeout 1 nslookup  $dns 
if [ $? = 0 ];then ERROR=0; echo; echo Online!  W00T ; echo ;echo using essid ; cat $TEMPDIR/ESSID ; sleep $CHECK_NET_TIMER ; Func_chk_net ; 
fi  #W00T
if [ $? -ge 1] ; then ERROR=1 ;echo ;echo FAIL!\ 
... Searching ; echo ; Func_Main ;
fi 
}
#### Main loop Funk
Func_MAIN () { while [ ERROR=1 ] ; do
Func_ifconfig_down ;
Func_iwlist_open Func_ifconfig_up ;
timeout $DHCP_TIMEOUT udhcpc $IFACE ;
Func_chk_net ;
Func_MAIN ;
done; 
}
#Prep 
mkdir $TEMPDIR
touch $TEMPDIR/scan
touch $TEMPDIR/scan1
touch $TEMPDIR/ESSID
# RunProgram
Func_ifconfig_down 
Func_iwlist_open Func_ifconfig_up 
timeout $DHCP_TIMEOUT udhcpc $IFACE 
Func_chk_net  
Func_MAIN 
echo This is the end, my only friend the end
Done; #actually i dont think it ever ends but i'm done writing it
#####################EOF#EOF#EOF#EOF#EOF#EOF#EOF#EOF#EOF#########

[edit] timeout

Added a timeout script to keep udhcpc from hanging everything. As we all know, dhcp should not take 60sec
INSTALL /usr/bin/timeout

#Newsgroups: comp.unix.admin,comp.unix.solaris,comp.unix.shell
#From: gwc@root.co.uk (Geoff Clare)
#Subject: Re: timeout -t <sec> <unix command> (Re: How to give rsh a shorter timeout?)
#Message-ID: <EoBxrs.223@root.co.uk>
#Date: Fri, 13 Feb 1998 18:23:52 GMT

#
# Conversion to bash v2 syntax done by Chet Ramey <chet@po.cwru.edu
# UNTESTED
#

prog=${0##*/}
usage="usage: $prog [-signal] [timeout] [:interval] [+delay] [--] <command>"

SIG=-TERM       # default signal sent to the process when the timer expires
timeout=60      # default timeout
interval=15     # default interval between checks if the process is still alive
delay=2         # default delay between posting the given signal and
                # destroying the process (kill -KILL)

while :
do
        case $1 in
        --)     shift; break ;;
        -*)     SIG=$1 ;;
        [0-9]*) timeout=$1 ;;
        :*)     EXPR='..\(.*\)' ; interval=`expr x"$1" : "$EXPR"` ;;
        +*)     EXPR='..\(.*\)' ; delay=`expr x"$1" : "$EXPR"` ;;
        *)      break ;;
        esac
        shift
done

case $# in
0)      echo "$prog: $usage" >&2 ; exit 2 ;;
esac

(
        for t in $timeout $delay
        do
                while (( $t > $interval ))
                do
                        sleep $interval
                        kill -0 $$ || exit
                        t=$(( $t - $interval ))
                done
                sleep $t
                kill $SIG $$ && kill -0 $$ || exit
                SIG=-KILL
        done
) 2> /dev/null &

exec "$@"

[edit] comments

not sure but i think one has to make the /tmp/ files manually

  • fixed as of v2

[edit] Am Improved Version Of wifiweasel

Looking carefully through the code there seemed to be logical errors in the control structure of the program. This version is supposed to be logically similar without the recursive function calls. I have made very limited use of it but am submitting it here in case its useful for others. I call it wifiweasel3.sh It also uses environment variables instead of temporary files, which may or may not be a good thing.

1) Copy it to your phone, 
2) chmod +x wifiweasel3.sh 
3) ensure that you have the timeout program above copied and executable. 
4) Run it - At first you can try 
  wifiweaselv3.sh -v 
  which gives you a verbose account of what is happening. 
  you can also do 
  wifiweasel start
  and wifiweasel stop
 
  which keeps it silently backgrounded. 

Here is the code:

#!/bin/sh
####### WifiWeasel ###### 
# Ver. 2               ##
#########################
# 08-07-22             ##
##        kd8ikt       ##
##  we.trekbeyond.org  ##
#########################
# Ver 3 Mark Winder 27/7/8
#########################
#
#install /usr/bin/wifiweasel
#
#Variables
IFACE=eth0
DHCP_TIMEOUT=5       # requires /usr/bin/timeout
CHECK_NET_TIMER=15   #secs
# call -v for debug to std out 
PIDFILE=/tmp/wifiweasel.pid 
[[ "$1" == '-v' ]] && debug=1 && shift
if [[ "$1" == 'start' ]] 
then 
   shift 
   wifiweasel3.sh "$@" & 
   echo $! > $PIDFILE 
   exit 
fi 
if [[ "$1" == 'stop' ]] 
then 
   if [[ -e $PIDFILE ]] 
   then 
     kill $(cat $PIDFILE) 
     rm $PIDFILE 
     echo "WiFiWeasel stopped"; 
   fi 
   exit 
fi 

#
#Functions
#
#### Scan Funk
Func_iwlist_open () 
{
  ESSID=$(iwlist $IFACE scanning | 
      awk -F '[ :=]+' '/(ESS|Freq|Qual)/{ printf $3" " } /Encr/{ print $4 }'  | 
      sort -k4 -k3nr |grep off | 
      head -n1| sed 's/^"//;s/".*$//'
    )
  [[ $debug ]] && echo Using ESSID $ESSID 
}
#### interface down Funk
Func_ifconfig_down () 
{
  killall udhcpc 
  ifconfig $IFACE down
}
#### iface up Funk
Func_ifconfig_up () 
{
  ifconfig $IFACE up
  iwconfig $IFACE essid $ESSID
}
#### Connection check Funk
# 
Func_net_ok ()	
{
  [[ $debug ]] && echo checking...   
  export dns=`cat /etc/resolv.conf |grep name |awk '{print $2}'`
  if timeout 1 nslookup  $dns > /dev/null 2>&1 
  then 
    [[ $debug ]] && echo Online!  $ESSID 
    return 0 # net is ok 
  else
    [[ $debug ]] && echo "FAIL! $?  ... Searching "
    return 1 # net not ok 
  fi 
}
# RunProgram
while [[ 1 ]] 
do 
   if [[ -z $ESSID ]] # no essid ? 
   then
     Func_ifconfig_down
     Func_iwlist_open
     Func_ifconfig_up
     timeout $DHCP_TIMEOUT udhcpc $IFACE > /dev/null 2>&1 
   fi 
   sleep $CHECK_NET_TIMER
   Func_net_ok || ESSID="" 
done 
#####################EOF#EOF#EOF#EOF#EOF#EOF#EOF#EOF#EOF#########


[edit] sandbox

[edit] iwscan perl

#!/usr/bin/perl
# Tim Osburn - tim@osburn.com
#
# install perl

$iwlist = "/sbin/iwlist eth0 scanning";

open scan, "$iwlist |";
while (<scan>) {
  if (/^\s+Cell (\S+) - Address: (\S+)/) {
    $CELL=$1;
    $ADDRESS=$2;
    # print "$1 $2";
    $INLOOP=1;
    }
  if (/^\s+ESSID:(\S+)/) {
    $ESSID=$1;
    print " $1";
    }
  if (/^\s+Frequency:\S+ \S+ \(Channel (\S+)\)/) {
    $CHAN=$1;
    print " $1";
    }
  if (/^\s+Quality=\S+\s+Signal level=(\S+).*/) {
    $SIGNAL=$1;
    print " $1";
    }
  if (/^\s+Encryption key:(\S+)/) {
    $ENCRYPTION=$1;
    print " $1\n";
    }
  }
close scan;

produces output in the form of "essid" channel signal_strength encryption_status


"ESSID_NAME1" 1 -82 on
"ESSID_NAME2" 1 -49 off

Personal tools

script to Auto connect to Open 802.11 wireless AP's

wifiweasel

wifiweasel v2 - once run this script takes control of the wireless interface, then detects and connects to strongest open wifi AP in the vicinity. Subsequently it checks the connectivity every X seconds. If the connection fails, the whole process repeats itself; this requires the timeout script below

 
#!/bin/sh
####### WifiWeasel ###### Ver. 2
######################### 08-07-22
##        kd8ikt       ##
##  we.trekbeyond.org  ##
#########################
#########################
#
#install /usr/bin/wifiweasel
#
#Variables
IFACE=eth0
DHCP_TIMEOUT=5       # requires /usr/bin/timeout
CHECK_NET_TIMER=15   #secs
TEMPDIR=/tmp/wifiweasel/
#
#Functions
#
#(dont touch unless you 
#know wtf your doing
#
#### Scan Funk
Func_iwlist_open () {
iwlist $IFACE scanning | awk -F '[ :=]+' '/(ESS|Freq|Qual)/{ printf $3" " } /Encr/{ print $4 }' \
    | sort -k4 -k3nr |grep -m1 off \
|awk '{print $1}' > /tmp/wifiweasel/scan
cat $TEMPDIR/scan |grep '"' -m1 > $TEMPDIR/scan1
sed /\"/s/\"//g $TEMPDIR/scan1 > $TEMPDIR/ESSID
echo 
echo Using ESSID
cat $TEMPDIR/ESSID
echo
}
#### interface down Funk
Func_ifconfig_down () {
killall udhcpc 
ifconfig $IFACE down
}
#### iface up Funk
Func_ifconfig_up () {
iwconfig $IFACE essid `cat $TEMPDIR/ESSID` 
}
#### Connection check Funk
Func_chk_net ()	{
echo checking...   
export dns=`cat /etc/resolv.conf |grep name |awk '{print $2}'`
timeout 1 nslookup  $dns 
if [ $=0 ];then ERROR=0; echo; echo Online!  W00T ; echo ;echo using essid ; cat $TEMPDIR/ESSID ; sleep $CHECK_NET_TIMER ; Func_chk_net ; 
fi  #W00T
if [ $=143 ] ; then ERROR=1 ;echo ;echo FAIL!\ 
... Searching ; echo ; Func_Main ;
fi 
}
#### Main loop Funk
Func_MAIN () { while [ ERROR=1 ] ; do
Func_ifconfig_down ;
Func_iwlist_open Func_ifconfig_up ;
timeout $DHCP_TIMEOUT udhcpc $IFACE ;
Func_chk_net ;
Func_MAIN ;
done; 
}
#Prep 
mkdir $TEMPDIR
touch $TEMPDIR/scan
touch $TEMPDIR/scan1
touch $TEMPDIR/ESSID
# RunProgram
Func_ifconfig_down 
Func_iwlist_open Func_ifconfig_up 
timeout $DHCP_TIMEOUT udhcpc $IFACE 
Func_chk_net  
Func_MAIN 
echo This is the end, my only friend the end
Done; #actually i dont think it ever ends but i'm done writing it
#####################EOF#EOF#EOF#EOF#EOF#EOF#EOF#EOF#EOF#########

timeout

Added a timeout script to keep udhcpc from hanging everything. As we all know, dhcp should not take 60sec
INSTALL /usr/bin/timeout

#Newsgroups: comp.unix.admin,comp.unix.solaris,comp.unix.shell
#From: gwc@root.co.uk (Geoff Clare)
#Subject: Re: timeout -t <sec> <unix command> (Re: How to give rsh a shorter timeout?)
#Message-ID: <EoBxrs.223@root.co.uk>
#Date: Fri, 13 Feb 1998 18:23:52 GMT

#
# Conversion to bash v2 syntax done by Chet Ramey <chet@po.cwru.edu
# UNTESTED
#

prog=${0##*/}
usage="usage: $prog [-signal] [timeout] [:interval] [+delay] [--] <command>"

SIG=-TERM       # default signal sent to the process when the timer expires
timeout=60      # default timeout
interval=15     # default interval between checks if the process is still alive
delay=2         # default delay between posting the given signal and
                # destroying the process (kill -KILL)

while :
do
        case $1 in
        --)     shift; break ;;
        -*)     SIG=$1 ;;
        [0-9]*) timeout=$1 ;;
        :*)     EXPR='..\(.*\)' ; interval=`expr x"$1" : "$EXPR"` ;;
        +*)     EXPR='..\(.*\)' ; delay=`expr x"$1" : "$EXPR"` ;;
        *)      break ;;
        esac
        shift
done

case $# in
0)      echo "$prog: $usage" >&2 ; exit 2 ;;
esac

(
        for t in $timeout $delay
        do
                while (( $t > $interval ))
                do
                        sleep $interval
                        kill -0 $$ || exit
                        t=$(( $t - $interval ))
                done
                sleep $t
                kill $SIG $$ && kill -0 $$ || exit
                SIG=-KILL
        done
) 2> /dev/null &

exec "$@"

comments

not sure but i think one has to make the /tmp/ files manually

  • fixed as of v2

sandbox

iwscan perl

#!/usr/bin/perl
# Tim Osburn - tim@osburn.com
#
# install perl

$iwlist = "/sbin/iwlist eth0 scanning";

open scan, "$iwlist |";
while (<scan>) {
  if (/^\s+Cell (\S+) - Address: (\S+)/) {
    $CELL=$1;
    $ADDRESS=$2;
    # print "$1 $2";
    $INLOOP=1;
    }
  if (/^\s+ESSID:(\S+)/) {
    $ESSID=$1;
    print " $1";
    }
  if (/^\s+Frequency:\S+ \S+ \(Channel (\S+)\)/) {
    $CHAN=$1;
    print " $1";
    }
  if (/^\s+Quality=\S+\s+Signal level=(\S+).*/) {
    $SIGNAL=$1;
    print " $1";
    }
  if (/^\s+Encryption key:(\S+)/) {
    $ENCRYPTION=$1;
    print " $1\n";
    }
  }
close scan;

produces output in the form of "essid" channel signal_strength encryption_status


"ESSID_NAME1" 1 -82 on
"ESSID_NAME2" 1 -49 off