How to use lpstat in an If statement?

HyperTrey · 04-17-2008, 11:14 AM

I have figured out that I can use the lpstat -v <name of printer> (and -a) to see if the printer has been successfully installed. However, I am unsure how to use that information in an if statement.

How would I go about doing this?

unSpawn · 04-17-2008, 11:47 AM

If you don't need output, then you only need the exit value (0, 1, 127, etc, etc). You can achieve that by piping output of the command through 'grep'. So your starting command is: "command 2>&1 | grep -q searchterm". Now you can use the exit value any way you like.

Code:

# With a "case" statement:
lpstat args 2>&1 | grep -m1 -q "searchterm"
case "$?" in
 0) got it;;
 *) echo no;;
esac

# Test:
lpstat args 2>&1 | grep -m1 -q "searchterm"
[ $? -eq 0 ] && echo got it || echo no

# Or incorporate it in your "if" statement:
if [ `lpstat args 2>&1 | grep -m1 -q "searchterm"` -eq 0 ]; then
 echo got it; else echo no
fi

# Or else just:
lpstat args 2>&1 | grep -m1 -q "searchterm" && echo got it || echo no

HyperTrey · 04-17-2008, 12:44 PM

Quote:

# With a "case" statement:
lpstat args 2>&1 | grep -m1 -q "searchterm"
case "$?" in
0) got it;;
*) echo no;;
esac

this one seems the best solution for what i need, however is this correct:

Code:

lpstat -v $printname 2>&1 | grep -m1 -q "searchterm"
case "$?" in
 0) echo printer installed correctly;;
 *) echo printer was no installed correctly, please try again;;
esac

HyperTrey · 04-22-2008, 06:59 AM

anything on if i set this up correctly?

unSpawn · 04-22-2008, 08:33 AM

Looks OK to me. Couple of remarks. It could be lpstat isn't available, or doesn't return a valid result due to some error, and beware of 'grep' though, w/o "-i" you need to get case right, so maybe (YMMV, please test):

Code:

__determinePrinterInstall() { 
PRINTER="$1"; CMD="lpstat"; which $CMD >/dev/null 2>&1 || return 127
RESULT=`$CMD -v $printname 2>&1`; [ $? -eq 1 -o -z "${RESULT}" ] && return 127
echo "${RESULT}" | grep -m1 -qi "$PRINTER" >/dev/null 2>&1
}

__determinePrinterInstall "searchterm"
case "$?" in
 0) echo "[SUCCESS]: printer \"$PRINTER\" installed correctly.";;
 1) echo "[FAIL]: printer \"$PRINTER\" was no installed correctly, retry.";;
 127) echo "[FATAL]: \"${CMD}\" not available or ran without output, exiting.";;
 *) echo "[FATAL]: unspecified error, exiting.";;
esac