How do I tell if a regular file does not exist in Bash?

I've used the following script to see if a file exists:

#!/bin/bash

FILE=$1     
if [ -f $FILE ]; then
   echo "File $FILE exists."
else
   echo "File $FILE does not exist."
fi

What's the correct syntax to use if I only want to check if the file does not exist?

#!/bin/bash

FILE=$1     
if [ $FILE does not exist ]; then
   echo "File $FILE does not exist."
fi

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Best Answer-推荐答案

The test command ([ here) has a "not" logical operator which is the exclamation point (similar to many other languages). Try this:

if [ ! -f /tmp/foo.txt ]; then
    echo "File not found!"
fi