Bash Script Conditions - linux

Question

I'm building a bash script to send an email based off the last command. I seem to be having difficulties. Outside of a script the command works fine but when putting it in script it doesn't give the desired outcome.
Here is snippet of script:
grep -vFxf /path/to/first/file /path/to/second/file > /path/to/output/file.txt
if [ -s file.txt ] || echo "file is empty";
then
swaks -t "1#email.com" -f "norply#email.com" --header "Subject: sample" --body "Empty"
else
swaks -t "1#email.com" -f "norply#email.com" --header "subject: sample" --body "Not Empty"
fi
I ran the commands outside of script and I can see that there is data but when I add the commands within script I get the empty output. Please advise . Thank you in advance .

Answer 1

Your condition will always be true, because if [ -s file.txt ] fails, the exit status of the ||-list is the exit status of echo, which is almost guaranteed to be 0. You want to move the echo out of the condition and into the body of the if statement. (And to simplify further, just set the body to a variable and call swaks after the if completes.
if [ -s file.txt ];
then
body="Not Empty"
else
echo "file is empty"
body="Empty"
fi
swaks -t "1#email.com" -f "norply#email.com" --header "subject: sample" --body "$body"
If the only reason you create file.txt is to check if it is empty or not, you can just put the grep command directly in the if condition:
if grep -vFxfq /atph/to/first/file /path/to/second/file; then
body="Not Empty"
else
echo "No output"
body="Empty"
fi
swaks -t "1#email.com" -f "norply#email.com" --header "subject: sample" --body "$body"