I to write a bash script to send an email when local host connection is refused and when the connection is open, it should not write an email. For example:
netcat -z localhost 8287
if [ $? -ne 0 ]; then
echo " Connection refused" |/usr/lib/sendmail -s "Port doesn't function " [email protected]
else
echo "open"
fi
When I fire this bash scriptit does't work. I replaced sendmail by mail, sendEmail also, but every time I am getting different errors.
The following works on my systems:
if ! nc -z $host $port; then
echo "This message intentionally left blank" | mail -s "TCP port $port is not open on $host" $emailaddress
else
: Do whatever you wanted to do
fi
If it doesn't on yours, run tail -f /var/log/maillog while you run the script to see why the message might not be getting delivered.
Try:
/usr/lib/sendmail -oi -t << EOF
Subject: Port doesn't function
To: [email protected]
Connection refused
EOF
Which should be fairly portable (as long as sendmail is found in /usr/lib, you may want to try a few other locations like /usr/sbin or just use sendmail for a $PATH lookup if it's not there).
-oi is to not consider a "." on a single line as a terminator (not needed here, but useful in the general case).
On POSIX compliant systems, you should also be able to use mailx:
echo Connection refused | mailx -s "Port doesn't function" [email protected]
All those assume the system has a properly configured mail transfer agent.
/var/log/maillogto your initial post