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

Question

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

Answer 1

You can do this:

[[ ! -f "$FILE" ]] && echo "File doesn't exist"

or

if [[ ! -f "$FILE" ]]; then
    echo "File doesn't exist"
fi

If you want to check for file and folder both, then use -e option instead of -f. -e returns true for regular files, directories, socket, character special files, block special files etc.

Answer 2

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

Answer 3

sometimes it may be handy to use && and || operators.

Like in (if you have command "test"):

test -b $FILE && echo File not there!

or

test -b $FILE || echo File there!

Answer 4

You should be careful about running test for an unquoted variable, because it might produce unexpected results:

$ [ -f ]
$ echo $?
0
$ [ -f "" ]
$ echo $?
1

The recommendation is usually to have the tested variable surrounded by double quotation marks:

#!/bin/sh
FILE=$1

if [ ! -f "$FILE" ]
then
   echo "File $FILE does not exist."
fi

Answer 5

[[ -f $FILE ]] || printf '%s does not exist!\n' "$FILE"

Also, it's possible that the file is a broken symbolic link, or a non-regular file, like e.g. a socket, device or fifo. For example, to add a check for broken symlinks:

if [[ ! -f $FILE ]]; then
    if [[ -L $FILE ]]; then
        printf '%s is a broken symlink!\n' "$FILE"
    else
        printf '%s does not exist!\n' "$FILE"
    fi
fi

Answer 6

Bash File Testing

-b filename - Block special file
-c filename - Special character file
-d directoryname - Check for directory Existence
-e filename - Check for file existence, regardless of type (node, directory, socket, etc.)
-f filename - Check for regular file existence not a directory
-G filename - Check if file exists and is owned by effective group ID
-G filename set-group-id - True if file exists and is set-group-id
-k filename - Sticky bit
-L filename - Symbolic link
-O filename - True if file exists and is owned by the effective user id
-r filename - Check if file is a readable
-S filename - Check if file is socket
-s filename - Check if file is nonzero size
-u filename - Check if file set-user-id bit is set
-w filename - Check if file is writable
-x filename - Check if file is executable

How to use:

#!/bin/bash
file=./file
if [ -e "$file" ]; then
    echo "File exists"
else 
    echo "File does not exist"
fi 

A test expression can be negated by using the ! operator

#!/bin/bash
file=./file
if [ ! -e "$file" ]; then
    echo "File does not exist"
else 
    echo "File exists"
fi