Get values and catch exit code in one line of BASH

Often it is helpful if a variable is only used when a command is successful.

FILE_SIZE=$(stat --format="%s" /bin/bash) && { 
 echo "Size is $FILE_SIZE"; 
} || { 
 echo "File size is unknown."; 
}

This becomes tricky if you used a pipe to parse the result because the pipe will fork a new shell completely isolated from the original command. Using PIPESTATUS it is possible to check the exit code of the previous command to the left and then it is easy to test the result.

HOST_IP=$(host $SOME_HOST_NAME | awk '{print $NF}'; [ ${PIPESTATUS[0]} -eq 0 ] ) && {
 echo "Host IP is $HOST_IP"
} || {
 echo "no such host"
}