shell, match a string in terminal output - linux

Question

i will go and see if my touch screen calibrated with a own script.
But i have really few experience with shell scripts. I hope anyone can help me.
My idea is it to execute xinput --list-pros <device> and check the terminal output with the entry ...(242): <no items>.
This is the option if the touch screen not calibrated else there are the x/y coordinates like ...(242): 1 22 333 4444.
In my script I will execute xinput --list-pros <device> and check with grep is there a entry (242) and then check the same line if there a entry <no items>. But i fail to read the output from xinput --list.
# read the terminal output from xinput
$xinput_output= less xinput --list-pros 7
while read $xinput_output
do
# check first line from output
grep "242" $xinput_output
if [ $? != 0]
then
break;
else
# found 242 check x/y coordinates
grep "<no items>" $xinput_ouput
if [ $? != 0]
then
#no x/y coordinates, execute xinput_calibration
xinput_calibration
exit 0
fi
fi
done < $1

Answer 1

Enclose your command with backtick or $():
var=`some command` # note no $ before var
# Or by $()
var=$(some command)
# then you can now use command's output
echo $var

Answer 2

Presumably you mean xinput --list-props
Either way, you need to execute the command properly in bash, and you need to assign the variable properly, so try this:
xinput_output=$(xinput --list-props 7)

Answer 3

Thanks for your help,
i had a solution which works.
But i will advance it a little bit. I will remove the 'touch' command and will write the './demo' output in a memory not in a file.
Not be confused I change 'xinput' for testing in my own skript './demo', this is a script with only few 'echo' commands to generate a terminal output.
#filename: touch
#!/bin/bash
touch /tmp/tmp.log
./demo > /tmp/tmp.log
calibration=$(grep controller /tmp/tmp.log)
if [ $? != 0 ]
then
echo "missing match, corrupt file\n"
exit 0
fi
if [[ $calibration == *"<no items>"* ]]
then
echo no calibration
#xinput_calibration
else
echo found x/y coodinates
fi
rm /tmp/tmp.log
exit0
test script:
#filename: demo
#!/bin/bash
echo 'cookie'
echo 'cookie'
echo 'cookie'
controller\:\ \<no\ items\>
echo 'cookie'
echo 'cookie'
echo 'cookie'
exit 0

Answer 4

i ****found** the solution**. :D \"/,
My problem was, with
tmp=$(./demo)
echo $tmp
you put out the terminal output from ./demo as string.
and with 'grep' you can't find a single line.
So you must type "${tmp}" to find the single line with grep.
#cache terminal output
tmp=$(./demo)
#find word in cache
match=$(echo "${tmp}" | grep 'controller')
echo $match