[ajauberg]

Hi,

I am creating a script that collects data from remote routers and reports this back to a central location. I do however have a problem with constructing the URL that shall be reported back because the global variable WGET which is used to build the string that shall be reported back is not treated as global, but is only updated locally within the loop:

#!/bin/sh

WIFI=ath0
BR=br0

# Update the MAC, IP address and peers of the AP
WGET=http://<mysite>/update2.php

IP=`ifconfig $BR | grep inet | cut -d B -f1 | sed s/[^0-9.]//g`
AP=`iwconfig $WIFI | grep Access | cut -d" " -f18`
ESSID=`iwconfig $WIFI | grep ESSID | cut -d\" -f2`
RATE=`iwconfig $WIFI | grep Rate | cut -d"M" -f1 | cut -b20-25 | cut -d" " -f1`
UPTIME=`cat /proc/uptime | cut -d"." -f1`
CLI=`cat /proc/net/arp | grep $BR | wc -l | sed s/[^0-9]//g`

WGET="$WGET?IP=$IP&AP=$AP&ESSID=$ESSID&UPTIME=$UPTIME&CLI=$CLI&RATE=$RATE"
echo $WGET

iwlist $WIFI peers | grep 'Quality' | while read line;
do
  MAC=`echo $line | cut -d" " -f1`
  QUAL=`echo $line | cut -d"=" -f2 | cut -d"/" -f1`
  SIG=`echo $line | cut -d"=" -f3 | cut -d" " -f1`
  NOISE=`echo $line | cut -d"=" -f4 | cut -d" " -f1`

  WGET="$WGET&MAC[]=$MAC&QUAL[]=$QUAL&SIG[]=$SIG&NOISE[]=$NOISE"
  echo $WGET
done

echo $WGET
#wget -O /dev/null "$WGET"

If you run the above script, the local WGET within the loop is updated and shows the complete URL with all peers, but the last WGET is not getting updated with the contents within the loop.

What can be done to update the WGET so it contains info from all peers?


BR

Arne-J.

[vsemaska]

The problem is when you pipe data to a loop a child process is created to run the loop. Any variable settings within the child process are not seen in the parent process. The thing to do is direct the output to a file and then use that in the loop.

iwlist $WIFI peers | grep 'Quality' > /tmp/tmp.tmp
while read line
    do
       .
       .
       .
    done < /tmp/tmp.tmp
rm -f /tmp/tmp.tmp

[ajauberg]

Thank you, it worked!

The updated script:

#!/bin/sh

WIFI=ath0
BR=br0
TMP=/tmp/tmp.tmp

# Update the MAC, IP address and peers of the AP
WGET=http://<mysite>/update.php

IP=`ifconfig $BR | grep inet | cut -d B -f1 | sed s/[^0-9.]//g`
AP=`iwconfig $WIFI | grep Access | cut -d" " -f18`
ESSID=`iwconfig $WIFI | grep ESSID | cut -d\" -f2`
RATE=`iwconfig $WIFI | grep Rate | cut -d"M" -f1 | cut -b20-25 | cut -d" " -f1`
UPTIME=`cat /proc/uptime | cut -d"." -f1`
CLI=`cat /proc/net/arp | grep $BR | wc -l | sed s/[^0-9]//g`

WGET="$WGET?IP=$IP&AP=$AP&ESSID=$ESSID&UPTIME=$UPTIME&CLI=$CLI&RATE=$RATE"
#echo $WGET

rm -f $TMP
iwlist $WIFI peers | grep 'Quality' > $TMP
while read line
do
  MAC=`echo $line | cut -d" " -f1`
  QUAL=`echo $line | cut -d"=" -f2 | cut -d"/" -f1`
  SIG=`echo $line | cut -d"=" -f3 | cut -d" " -f1`
  NOISE=`echo $line | cut -d"=" -f4 | cut -d" " -f1`

  WGET="$WGET&MAC[]=$MAC&QUAL[]=$QUAL&SIG[]=$SIG&NOISE[]=$NOISE"
#  echo $WGET
done < $TMP

echo $WGET
#wget -O /dev/null "$WGET"