Check if file exists and continue else exit in Bash

问题

I have a script that is one script in a chain of others that sends an email.

At the start of the script I want to check if a file exists and continue only if it exists, otherwise just quit.

Here is the start of my script:

if [ ! -f /scripts/alert ];
then
    echo "File not found!" && exit 0
else
        continue
fi

However I keep getting a message saying:

line 10: continue: only meaningful in a `for', `while', or `until' loop

Any pointers?

回答1:

Change it to this:

{
if [ ! -f /scripts/alert ]; then
    echo "File not found!"
    exit 0
fi
}

A conditional isn't a loop, and there's no place you need to jump to. Execution simply continues after the conditional anyway.

(I also removed the needless &&. Not that it should happen, but just in case the echo fails there's no reason not to exit.)

回答2:

Your problem is with the continue line which is normally used to skip to the next iteration of a for or while loop.

Therefore just removing the else part of your script should allow it to work.

回答3:

Yes. Drop the else continue. It's entirely unneeded.

来源：https://stackoverflow.com/questions/9146136/check-if-file-exists-and-continue-else-exit-in-bash