Linux打印状态检查脚本

Question

I'm trying to write a script that checks the status of a printer (it will be set as a chron job). If the printer is running, It'll echo out that the printer is enabled. If the printer is not, it should send an e mail with lpstat info. Either way, it should be writing the lpstat info to a txt file which will only be e mailed in the case that the printer is down. Here is the script:

#This script is designed to check the status of a printer.
#The printer's status attributes will be written to a text file.
#Finally, ane mail will be sent from the command line containing the text file.
lpstat -t -h <host name> -p <printer name> > /tmp/printerstatus.txt
RC=cat /tmp/printerstatus.txt | grep "enabled"
if [ -z $RC ]
then
mail -s "Printer Status" ****.********@******.com < /tmp/printerstatus.txt
else
echo "Printer Enabled";
fi

Here are the errors I'm getting:

/tmp/printerstatus.txt: line 1: scheduler: command not found
/tmp/printerstatus.txt: line 2: system: command not found
/tmp/printerstatus.txt: line 3: device: command not found
/tmp/printerstatus.txt: line 4: <printer name>: command not found
/tmp/printerstatus.txt: line 5: printer: command not found
/tmp/printerstatus.txt: line 6: Paused: command not found
/tmp/printerstatus.txt: line 7: printer: command not found
/tmp/printerstatus.txt: line 8: Paused: command not found
./checkprinter.sh: line 12: syntax error: unexpected end of file

I'm trying to run the script from the /home directory. Thanks in advance for the suggestions :)

Answer 1

This line

RC=cat /tmp/printerstatus.txt | grep "enabled"

attempts to execute /tmp/printerstatus.txt (why is its execution permission set?) as a shell script. You want to use command substitution to capture the output of the entire pipeline (which, by the way, is a useless use of cat ) in the variable RC .

RC=$(grep "enabled" /tmp/printerstatus.txt)

You can reduce the script further to

if lpstat -t -h <host name> -p <printer name> | tee /tmp/printerstatus.txt | grep -q "enabled"; then
    mail -s "Printer Status" ****.********@******.com < /tmp/printerstatus.txt
else
    echo "Printer Enabled";
fi

Answer 2

RC=cat /tmp/printerstatus.txt | grep "enabled"

This is causing the errors.

The second argument to grep is a filename. cat`ting to grep is redundant. You should

RC=$(grep "enabled" /tmp/printerstatus.txt)