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


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
2017/01/25
1
3323
1/25/2017 5:37:06 AM

Accepted Answer

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
2014/06/13
4600
6/13/2014 2:55:36 PM

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 
2016/07/08

You can negate an expression with "!":

#!/bin/bash
FILE=$1

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

The relevant man page is man test or, equivalently, man [ -- or help test or help [ for the built-in bash command.

2017/07/07

[[ -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
2014/09/14

It's worth mentioning that if you need to execute a single command you can abbreviate

if [ ! -f "$file" ]; then
    echo "$file"
fi

to

test -f "$file" || echo "$file"

or

[ -f "$file" ] || echo "$file"
2014/09/14

I prefer to do the following one-liner, in POSIX shell compatible format:

$ [ -f "/$DIR/$FILE" ] || echo "$FILE NOT FOUND"

$ [ -f "/$DIR/$FILE" ] && echo "$FILE FOUND"

For a couple of commands, like I would do in a script:

$  [ -f "/$DIR/$FILE" ] || { echo "$FILE NOT FOUND" ; exit 1 ;}

Once I started doing this, I rarely use the fully typed syntax anymore!!

2015/04/15

Source: https://stackoverflow.com/questions/638975
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