Related
This checks if a file exists:
#!/bin/bash
FILE=$1
if [ -f $FILE ]; then
echo "File $FILE exists."
else
echo "File $FILE does not exist."
fi
How do I only check if the file does not exist?
The test command (written as [ here) has a "not" logical operator, ! (exclamation mark):
if [ ! -f /tmp/foo.txt ]; then
echo "File not found!"
fi
Bash File Testing
-b filename - Block special file
-c filename - Special character file
-d directoryname - Check for directory Existence
-e filename - Check for file existence, regardless of type (node, directory, socket, etc.)
-f filename - Check for regular file existence not a directory
-G filename - Check if file exists and is owned by effective group ID
-G filename set-group-id - True if file exists and is set-group-id
-k filename - Sticky bit
-L filename - Symbolic link
-O filename - True if file exists and is owned by the effective user id
-r filename - Check if file is a readable
-S filename - Check if file is socket
-s filename - Check if file is nonzero size
-u filename - Check if file set-user-id bit is set
-w filename - Check if file is writable
-x filename - Check if file is executable
How to use:
#!/bin/bash
file=./file
if [ -e "$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
Negate the expression inside test (for which [ is an alias) using !:
#!/bin/bash
FILE=$1
if [ ! -f "$FILE" ]
then
echo "File $FILE does not exist"
fi
The relevant man page is man test or, equivalently, man [ -- or help test or help [ for the built-in bash command.
Alternatively (less commonly used) you can negate the result of test using:
if ! [ -f "$FILE" ]
then
echo "File $FILE does not exist"
fi
That syntax is described in "man 1 bash" in sections "Pipelines" and "Compound Commands".
[[ -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' "$FILE"
fi
fi
It's worth mentioning that if you need to execute a single command you can abbreviate
if [ ! -f "$file" ]; then
echo "$file"
fi
to
test -f "$file" || echo "$file"
or
[ -f "$file" ] || echo "$file"
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!!
To test file existence, the parameter can be any one of the following:
-e: Returns true if file exists (regular file, directory, or symlink)
-f: Returns true if file exists and is a regular file
-d: Returns true if file exists and is a directory
-h: Returns true if file exists and is a symlink
All the tests below apply to regular files, directories, and symlinks:
-r: Returns true if file exists and is readable
-w: Returns true if file exists and is writable
-x: Returns true if file exists and is executable
-s: Returns true if file exists and has a size > 0
Example script:
#!/bin/bash
FILE=$1
if [ -f "$FILE" ]; then
echo "File $FILE exists"
else
echo "File $FILE does not exist"
fi
You can do this:
[[ ! -f "$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.
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 $FILE does not exist."
fi
In
[ -f "$file" ]
the [ command does a stat() (not lstat()) system call on the path stored in $file and returns true if that system call succeeds and the type of the file as returned by stat() is "regular".
So if [ -f "$file" ] returns true, you can tell the file does exist and is a regular file or a symlink eventually resolving to a regular file (or at least it was at the time of the stat()).
However if it returns false (or if [ ! -f "$file" ] or ! [ -f "$file" ] return true), there are many different possibilities:
the file doesn't exist
the file exists but is not a regular file (could be a device, fifo, directory, socket...)
the file exists but you don't have search permission to the parent directory
the file exists but that path to access it is too long
the file is a symlink to a regular file, but you don't have search permission to some of the directories involved in the resolution of the symlink.
... any other reason why the stat() system call may fail.
In short, it should be:
if [ -f "$file" ]; then
printf '"%s" is a path to a regular file or symlink to regular file\n' "$file"
elif [ -e "$file" ]; then
printf '"%s" exists but is not a regular file\n' "$file"
elif [ -L "$file" ]; then
printf '"%s" exists, is a symlink but I cannot tell if it eventually resolves to an actual file, regular or not\n' "$file"
else
printf 'I cannot tell if "%s" exists, let alone whether it is a regular file or not\n' "$file"
fi
To know for sure that the file doesn't exist, we'd need the stat() system call to return with an error code of ENOENT (ENOTDIR tells us one of the path components is not a directory is another case where we can tell the file doesn't exist by that path). Unfortunately the [ command doesn't let us know that. It will return false whether the error code is ENOENT, EACCESS (permission denied), ENAMETOOLONG or anything else.
The [ -e "$file" ] test can also be done with ls -Ld -- "$file" > /dev/null. In that case, ls will tell you why the stat() failed, though the information can't easily be used programmatically:
$ file=/var/spool/cron/crontabs/root
$ if [ ! -e "$file" ]; then echo does not exist; fi
does not exist
$ if ! ls -Ld -- "$file" > /dev/null; then echo stat failed; fi
ls: cannot access '/var/spool/cron/crontabs/root': Permission denied
stat failed
At least ls tells me it's not because the file doesn't exist that it fails. It's because it can't tell whether the file exists or not. The [ command just ignored the problem.
With the zsh shell, you can query the error code with the $ERRNO special variable after the failing [ command, and decode that number using the $errnos special array in the zsh/system module:
zmodload zsh/system
ERRNO=0
if [ ! -f "$file" ]; then
err=$ERRNO
case $errnos[err] in
("") echo exists, not a regular file;;
(ENOENT|ENOTDIR)
if [ -L "$file" ]; then
echo broken link
else
echo does not exist
fi;;
(*) syserror -p "can't tell: " "$err"
esac
fi
(beware the $errnos support was broken with some versions of zsh when built with recent versions of gcc).
There are three distinct ways to do this:
Negate the exit status with bash (no other answer has said this):
if ! [ -e "$file" ]; then
echo "file does not exist"
fi
Or:
! [ -e "$file" ] && echo "file does not exist"
Negate the test inside the test command [ (that is the way most answers before have presented):
if [ ! -e "$file" ]; then
echo "file does not exist"
fi
Or:
[ ! -e "$file" ] && echo "file does not exist"
Act on the result of the test being negative (|| instead of &&):
Only:
[ -e "$file" ] || echo "file does not exist"
This looks silly (IMO), don't use it unless your code has to be portable to the Bourne shell (like the /bin/sh of Solaris 10 or earlier) that lacked the pipeline negation operator (!):
if [ -e "$file" ]; then
:
else
echo "file does not exist"
fi
envfile=.env
if [ ! -f "$envfile" ]
then
echo "$envfile does not exist"
exit 1
fi
To reverse a test, use "!".
That is equivalent to the "not" logical operator in other languages. Try this:
if [ ! -f /tmp/foo.txt ];
then
echo "File not found!"
fi
Or written in a slightly different way:
if [ ! -f /tmp/foo.txt ]
then echo "File not found!"
fi
Or you could use:
if ! [ -f /tmp/foo.txt ]
then echo "File not found!"
fi
Or, presing all together:
if ! [ -f /tmp/foo.txt ]; then echo "File not found!"; fi
Which may be written (using then "and" operator: &&) as:
[ ! -f /tmp/foo.txt ] && echo "File not found!"
Which looks shorter like this:
[ -f /tmp/foo.txt ] || echo "File not found!"
The test thing may count too. It worked for me (based on Bash Shell: Check File Exists or Not):
test -e FILENAME && echo "File exists" || echo "File doesn't exist"
This code also working .
#!/bin/bash
FILE=$1
if [ -f $FILE ]; then
echo "File '$FILE' Exists"
else
echo "The File '$FILE' Does Not Exist"
fi
The simplest way
FILE=$1
[ ! -e "${FILE}" ] && echo "does not exist" || echo "exists"
This shell script also works for finding a file in a directory:
echo "enter file"
read -r a
if [ -s /home/trainee02/"$a" ]
then
echo "yes. file is there."
else
echo "sorry. file is not there."
fi
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 $FILE || echo File there!
If you want to use test instead of [], then you can use ! to get the negation:
if ! test "$FILE"; then
echo "does not exist"
fi
You can also group multiple commands in the one liner
[ -f "filename" ] || ( echo test1 && echo test2 && echo test3 )
or
[ -f "filename" ] || { echo test1 && echo test2 && echo test3 ;}
If filename doesn't exit, the output will be
test1
test2
test3
Note: ( ... ) runs in a subshell, { ... ;} runs in the same shell.
I was given the task of making a remove script that imitates the rm command. As you know, the rm command deletes all files if you were to type something like rm file1 file2. Using this example, my script would only delete file2. Can anyone help me on how to make it so my remove script would delete all files listed? My script is below. I apologise if its a little messy, I am new to coding.
#!/bin/bash
function directory(){
#Checks if deleted directory & .restore.info file exists
#If they don't exist, it creates them
if [ ! -d ~/deleted ]
then
mkdir ~/deleted
fi
if [ ! -f ~/.restore.info ]
then
touch ~/.restore.info
fi
}
function movefile(){
#not currently using
mv "$1" ~/deleted/$1
echo "file moved to recycle bin"
}
function error_conditions(){
#not currently using
#Prints error messages and checks if file is in project directory
if [ ! -f ~/project ]
then
echo "cannot remove $filename: no such file or directory"
elif [ -d ~/project ]
then
echo "cannot remove $filename: is a directory"
else
echo "missing operand"
fi
}
function delete_file(){
#Gets inode for filename
#Takes user input and puts file wherever based on user input
inode=$(stat -c%i "$filename")
pwd=$(readlink -e $filename)
if "$interactive"
then
if [ "$verbose" = true ]; then
read -p "Are you sure you want to delete $filename? " user_input
if [ $user_input == "y" ] || [ $user_input == "Y" ] || [ $user_input == "yes" ] || [ $user_input == "Yes" ];
then
mv $filename ~/deleted/${filename}_$inode
#moves deleted file to deleted directory (with inode at end)
echo ${filename}_$inode:$pwd>>~/.restore.info
#stores info of removed file in .restore.info (with path)
echo "removed '$filename'"
else
echo "Nothing has been deleted"
fi
else
read -p "Are you sure you want to delete $filename? " user_input
if [ $user_input == "y" ] || [ $user_input == "Y" ] || [ $user_input == "yes" ] || [ $user_input == "Yes"];
then
mv "$filename" ~/deleted/${filename}_$inode
echo ${filename}_$inode:$pwd>>~/.restore.info
else
echo "Aborted"
fi
fi
elif "$verbose"
then
mv "$filename" ~/deleted/${filename}_$inode
echo ${filename}_$inode:$inode:pwd>>~/.restore.info
echo "removed '$filename'"
else
mv "$filename" ~/deleted/${filename}_$inode
echo ${filename}_$inode:$pwd>>~/.restore.info
echo "Executed"
fi
}
#Setting all flags to false
interactive=false
verbose=false
recursive=false
while getopts :ivr optionvar
do
case "$optionvar" in
i) interactive=true;;
v) verbose=true;;
r) recursive=true;;
esac
done
shift $((OPTIND-1)) #process arguments.
#doing error commands with help of recursive
for i in $*
do
filename=$i
basefile=$(basename $i)
if [ "$filename" == " " ];
then
echo "No filename provcided"
elif [ -d $filename ];
then
if [ ! $recursive = true ];
then
echo "Directory name provided, please provide a file"
fi
elif [ ! -f $filename ];
then
echo "File does not exist"
# elif [ "$basefile" == "safe_rm" ]
# then
# echo "Attempting to delete safe_rm"
fi
done
#################################M A I N###############################
directory
delete_file $*
#error_conditions $* #- this gives me duplicate output lines
#movefile "$#" - this gives me an unnecessary "mv: cannot stat" output line
I'm not going to do a detailed code review of your whole script, but here are a few notes.
You are looping over the arguments in the main part of your script, but then you're calling the delete function with multiple arguments. That function has no looping in it. Move the loop from main() to delete_files() (and note that I pluralized its name for clarity).
And speaking of main(), you might as well encapsulate that code (option processing, function dispatch, etc.) in a function of that name, then at the bottom of your script have a line that calls it: main "$#"
Don't use $* unless you need what it does and understand its use - instead use "$#" almost always and always quote it (with very rare exceptions)
Use indentation consistently
If your script doesn't need to be portable to shells other than Bash, then use Bash-specific features such as [[ ]] instead of [ ]
You're using both methods of naming a function at the same time (function f()). Use one or the other - parens are preferred over using function - so f () { ...; }
Use more quotes, some examples:
pwd=$(readlink -e "$filename")
mv "$filename" ~/deleted/"${filename}_$inode"
echo "${filename}_$inode:$pwd" >> ~/.restore.info
But I don't recommend using tilde (~) in scripts - use $HOME instead. And if you need to look up a user's home directory, use getent instead of other methods.
I've written script to temporarily delete files in Unix and then save the file path so they can be restored. I have 2 functions, one to delete files, and one to delete a directory that also recursively deletes files. I have the appropriate commands to recognize the directory name and path as well as checking to see if files remain in the directory and then deleting them. At first I was getting an infinite loop but I made some changes and now, it's saying there is no such file or directory when I try to delete a directory. It still runs through the code but it doesn't delete any files. Can anyone figure this out?
#!/bin/bash
#checks to see if deleted folder exists. If it doesn't, it is created.
if [ ! -d ~/deleted ];
then
mkdir ~/deleted
fi
if [ ! -f ~/.restore.info ] ;
then
touch ~/.restore.info
fi
function recur_delete {
dir=$1 #this will indicate the directory name only
dirpath=$(dirname $dir) #gets the directory path
if [ "$( ls -A /$dirpath/$dir)" ]; #determines if the directory contains files.
then
filename=$(find dirpath/dir -type f -printf "%f\n" | head -1)
delete_file $filename #filename is found and sent to delete_file function to be deleted.
recur_delete $dir #function is called again to see if more files are present.
else
echo Directory is empty, the directory will be deleted
echo $dirpath/$dir >> ~/.restore.info
rmdir ${dirpath/$dir}
fi
}
function delete_file {
inode=$(stat -c%i $filename) #grabs inode # for the chosen filename.
filename=$1 #reinitializes the variable filename as the first argument
pwd=$(readlink -e $filename) #This gets the entire path for the chosen file
if $interactive
then
if [ $verbose = true ];
then
read -p "Are you SURE you want to delete $filename ????" i_input
if [ $i_input == "y" ] || [ $i_input == "Y" ];
then
mv $filename ~/deleted/${filename}_$inode
echo ${filename}_$inode:$pwd >> ~/.restore.info
echo $filename has been deleted. Congrats.
else
echo Nothing has been done, the file or files remain.
fi
else
read -p "Are you SURE you want to delete $filename ????" i_input
if [ $i_input == "y" ] || [ $i_input == "Y" ];
then
mv $filename ~/deleted/${filename}_$inode
echo ${filename}_$inode:$pwd >> ~/.restore.info
else
echo Aborted
fi
fi
elif $verbose
then
mv $filename ~/deleted/${filename}_$inode
echo ${filename}_$inode:$pwd >> ~/.restore.info
echo $filename has been deleted. Congrats.
else
mv $filename ~/deleted/${filename}_$inode
echo ${filename}_$inode:$pwd >> ~/.restore.info
echo Executed
fi
}
interactive=false
verbose=false
recursive=false
while getopts ivr OPTION
do
case $OPTION in
i) interactive=true;;
v) verbose=true;;
r) recursive=true;;
esac
done
shift $[OPTIND-1]
for i in $*
do
filename=$i
basefile=$(basename $i)
if [ "$i" == "" ];
then
echo No file provided
elif [ -d $filename ];
then
if [ $recursive = true ];
then
recur_delete $filename
else
echo This is a directory, please provide a file name.
fi
elif [ ! -f $filename ];
then
echo File does not exist
elif [ "$basefile" == "safe_rm" ];
then
echo Attempting to delete safe_rm - operation aborted!!!!
#This is the line that takes the filename to be deleted and modifies the
#experience based on what the user wants.
else
delete_file $filename
fi
done
This seems super-complicated. How about building something around
$ mkdir ~/.trashbin
$ mv /absolute/path/to/dir/or/file ~/.trashbin
for temp delete and then
$ mv ~/.trashbin/absolute/path/to/dir /absolute/path/to/dir
for restore?
You need one little fragment of code to get the old absolute path with the ~/.trashbin deleted, but that's simple.
Update
Aaah, it's the silly professor problem. I resemble that.
Okay, here's the deal: in any recursion, there has to be something that "gets smaller" in some sense with each call, and finally gets to the point where you stop recurring. In your case, that should be the results of ls -A. Step away from the code and examine what you really get from ls -A on an empty directory, and whether that evaluates to 0 or non-zero in that if. Hint: I bet it never does.
I'm trying to write an extremely simple script in Ubuntu which would allow me to pass it either a filename or a directory, and be able to do something specific when it's a file, and something else when it's a directory. The problem I'm having is when the directory name, or probably files too, has spaces or other escapable characters are in the name.
Here's my basic code down below, and a couple tests.
#!/bin/bash
PASSED=$1
if [ -d "${PASSED}" ] ; then
echo "$PASSED is a directory";
else
if [ -f "${PASSED}" ]; then
echo "${PASSED} is a file";
else
echo "${PASSED} is not valid";
exit 1
fi
fi
And here's the output:
andy#server~ $ ./scripts/testmove.sh /home/andy/
/home/andy/ is a directory
andy#server~ $ ./scripts/testmove.sh /home/andy/blah.txt
/home/andy/blah.txt is a file
andy#server~ $ ./scripts/testmove.sh /home/andy/blah\ with\ a\ space.txt
/home/andy/blah with a space.txt is not valid
andy#server~ $ ./scripts/testmove.sh /home/andy\ with\ a\ space/
/home/andy with a space/ is not valid
All of those paths are valid, and exist.
That should work. I am not sure why it's failing. You're quoting your variables properly. What happens if you use this script with double [[ ]]?
if [[ -d $PASSED ]]; then
echo "$PASSED is a directory"
elif [[ -f $PASSED ]]; then
echo "$PASSED is a file"
else
echo "$PASSED is not valid"
exit 1
fi
Double square brackets is a bash extension to [ ]. It doesn't require variables to be quoted, not even if they contain spaces.
Also worth trying: -e to test if a path exists without testing what type of file it is.
At least write the code without the bushy tree:
#!/bin/bash
PASSED=$1
if [ -d "${PASSED}" ]
then echo "${PASSED} is a directory";
elif [ -f "${PASSED}" ]
then echo "${PASSED} is a file";
else echo "${PASSED} is not valid";
exit 1
fi
When I put that into a file "xx.sh" and create a file "xx sh", and run it, I get:
$ cp /dev/null "xx sh"
$ for file in . xx*; do sh "$file"; done
. is a directory
xx sh is a file
xx.sh is a file
$
Given that you are having problems, you should debug the script by adding:
ls -ld "${PASSED}"
This will show you what ls thinks about the names you pass the script.
Using -f and -d switches on /bin/test:
F_NAME="${1}"
if test -f "${F_NAME}"
then
echo "${F_NAME} is a file"
elif test -d "${F_NAME}"
then
echo "${F_NAME} is a directory"
else
echo "${F_NAME} is not valid"
fi
Using the "file" command may be useful for this:
#!/bin/bash
check_file(){
if [ -z "${1}" ] ;then
echo "Please input something"
return;
fi
f="${1}"
result="$(file $f)"
if [[ $result == *"cannot open"* ]] ;then
echo "NO FILE FOUND ($result) ";
elif [[ $result == *"directory"* ]] ;then
echo "DIRECTORY FOUND ($result) ";
else
echo "FILE FOUND ($result) ";
fi
}
check_file "${1}"
Output examples :
$ ./f.bash login
DIRECTORY FOUND (login: directory)
$ ./f.bash ldasdas
NO FILE FOUND (ldasdas: cannot open `ldasdas' (No such file or directory))
$ ./f.bash evil.php
FILE FOUND (evil.php: PHP script, ASCII text)
FYI: the answers above work but you can use -s to help in weird situations by checking for a valid file first:
#!/bin/bash
check_file(){
local file="${1}"
[[ -s "${file}" ]] || { echo "is not valid"; return; }
[[ -d "${file}" ]] && { echo "is a directory"; return; }
[[ -f "${file}" ]] && { echo "is a file"; return; }
}
check_file ${1}
Using stat
function delete_dir () {
type="$(stat --printf=%F "$1")"
if [ $? -ne 0 ]; then
echo "$1 directory does not exist. Nothing to delete."
elif [ "$type" == "regular file" ]; then
echo "$1 is a file, not a directory."
exit 1
elif [ "$type" == "directory" ]; then
echo "Deleting $1 directory."
rm -r "$1"
fi
}
function delete_file () {
type="$(stat --printf=%F "$1")"
if [ $? -ne 0 ]; then
echo "$1 file does not exist. Nothing to delete."
elif [ "$type" == "directory" ]; then
echo "$1 is a regular file, not a directory."
exit 1
elif [ "$type" == "regular file" ]; then
echo "Deleting $1 regular file."
rm "$1"
fi
}
https://linux.die.net/man/2/stat
https://en.m.wikipedia.org/wiki/Unix_file_types
A more elegant solution
echo "Enter the file name"
read x
if [ -f $x ]
then
echo "This is a regular file"
else
echo "This is a directory"
fi
Answer based on the title:
Check if passed argument is file or directory in Bash
This works also if the provided argument has a trailing slash .e.g. dirname/
die() { echo $* 1>&2; exit 1; }
# This is to remove the the slash at the end: dirName/ -> dirName
fileOrDir=$(basename "$1")
( [ -d "$fileOrDir" ] || [ -f "$fileOrDir" ] ) && die "file or directory $fileOrDir already exists"
Testing:
mkdir mydir
touch myfile
command dirName
# file or directory mydir already exists
command dirName/
# file or directory mydir already exists
command filename
# file or directory myfile already exists
#!/bin/bash
echo "Please Enter a file name :"
read filename
if test -f $filename
then
echo "this is a file"
else
echo "this is not a file"
fi
One liner
touch bob; test -d bob && echo 'dir' || (test -f bob && echo 'file')
result is true (0)(dir) or true (0)(file) or false (1)(neither)
This should work:
#!/bin/bash
echo "Enter your Path:"
read a
if [[ -d $a ]]; then
echo "$a is a Dir"
elif [[ -f $a ]]; then
echo "$a is the File"
else
echo "Invalid path"
fi
This checks if a file exists:
#!/bin/bash
FILE=$1
if [ -f $FILE ]; then
echo "File $FILE exists."
else
echo "File $FILE does not exist."
fi
How do I only check if the file does not exist?
The test command (written as [ here) has a "not" logical operator, ! (exclamation mark):
if [ ! -f /tmp/foo.txt ]; then
echo "File not found!"
fi
Bash File Testing
-b filename - Block special file
-c filename - Special character file
-d directoryname - Check for directory Existence
-e filename - Check for file existence, regardless of type (node, directory, socket, etc.)
-f filename - Check for regular file existence not a directory
-G filename - Check if file exists and is owned by effective group ID
-G filename set-group-id - True if file exists and is set-group-id
-k filename - Sticky bit
-L filename - Symbolic link
-O filename - True if file exists and is owned by the effective user id
-r filename - Check if file is a readable
-S filename - Check if file is socket
-s filename - Check if file is nonzero size
-u filename - Check if file set-user-id bit is set
-w filename - Check if file is writable
-x filename - Check if file is executable
How to use:
#!/bin/bash
file=./file
if [ -e "$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
Negate the expression inside test (for which [ is an alias) using !:
#!/bin/bash
FILE=$1
if [ ! -f "$FILE" ]
then
echo "File $FILE does not exist"
fi
The relevant man page is man test or, equivalently, man [ -- or help test or help [ for the built-in bash command.
Alternatively (less commonly used) you can negate the result of test using:
if ! [ -f "$FILE" ]
then
echo "File $FILE does not exist"
fi
That syntax is described in "man 1 bash" in sections "Pipelines" and "Compound Commands".
[[ -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' "$FILE"
fi
fi
It's worth mentioning that if you need to execute a single command you can abbreviate
if [ ! -f "$file" ]; then
echo "$file"
fi
to
test -f "$file" || echo "$file"
or
[ -f "$file" ] || echo "$file"
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!!
To test file existence, the parameter can be any one of the following:
-e: Returns true if file exists (regular file, directory, or symlink)
-f: Returns true if file exists and is a regular file
-d: Returns true if file exists and is a directory
-h: Returns true if file exists and is a symlink
All the tests below apply to regular files, directories, and symlinks:
-r: Returns true if file exists and is readable
-w: Returns true if file exists and is writable
-x: Returns true if file exists and is executable
-s: Returns true if file exists and has a size > 0
Example script:
#!/bin/bash
FILE=$1
if [ -f "$FILE" ]; then
echo "File $FILE exists"
else
echo "File $FILE does not exist"
fi
You can do this:
[[ ! -f "$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.
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 $FILE does not exist."
fi
In
[ -f "$file" ]
the [ command does a stat() (not lstat()) system call on the path stored in $file and returns true if that system call succeeds and the type of the file as returned by stat() is "regular".
So if [ -f "$file" ] returns true, you can tell the file does exist and is a regular file or a symlink eventually resolving to a regular file (or at least it was at the time of the stat()).
However if it returns false (or if [ ! -f "$file" ] or ! [ -f "$file" ] return true), there are many different possibilities:
the file doesn't exist
the file exists but is not a regular file (could be a device, fifo, directory, socket...)
the file exists but you don't have search permission to the parent directory
the file exists but that path to access it is too long
the file is a symlink to a regular file, but you don't have search permission to some of the directories involved in the resolution of the symlink.
... any other reason why the stat() system call may fail.
In short, it should be:
if [ -f "$file" ]; then
printf '"%s" is a path to a regular file or symlink to regular file\n' "$file"
elif [ -e "$file" ]; then
printf '"%s" exists but is not a regular file\n' "$file"
elif [ -L "$file" ]; then
printf '"%s" exists, is a symlink but I cannot tell if it eventually resolves to an actual file, regular or not\n' "$file"
else
printf 'I cannot tell if "%s" exists, let alone whether it is a regular file or not\n' "$file"
fi
To know for sure that the file doesn't exist, we'd need the stat() system call to return with an error code of ENOENT (ENOTDIR tells us one of the path components is not a directory is another case where we can tell the file doesn't exist by that path). Unfortunately the [ command doesn't let us know that. It will return false whether the error code is ENOENT, EACCESS (permission denied), ENAMETOOLONG or anything else.
The [ -e "$file" ] test can also be done with ls -Ld -- "$file" > /dev/null. In that case, ls will tell you why the stat() failed, though the information can't easily be used programmatically:
$ file=/var/spool/cron/crontabs/root
$ if [ ! -e "$file" ]; then echo does not exist; fi
does not exist
$ if ! ls -Ld -- "$file" > /dev/null; then echo stat failed; fi
ls: cannot access '/var/spool/cron/crontabs/root': Permission denied
stat failed
At least ls tells me it's not because the file doesn't exist that it fails. It's because it can't tell whether the file exists or not. The [ command just ignored the problem.
With the zsh shell, you can query the error code with the $ERRNO special variable after the failing [ command, and decode that number using the $errnos special array in the zsh/system module:
zmodload zsh/system
ERRNO=0
if [ ! -f "$file" ]; then
err=$ERRNO
case $errnos[err] in
("") echo exists, not a regular file;;
(ENOENT|ENOTDIR)
if [ -L "$file" ]; then
echo broken link
else
echo does not exist
fi;;
(*) syserror -p "can't tell: " "$err"
esac
fi
(beware the $errnos support was broken with some versions of zsh when built with recent versions of gcc).
There are three distinct ways to do this:
Negate the exit status with bash (no other answer has said this):
if ! [ -e "$file" ]; then
echo "file does not exist"
fi
Or:
! [ -e "$file" ] && echo "file does not exist"
Negate the test inside the test command [ (that is the way most answers before have presented):
if [ ! -e "$file" ]; then
echo "file does not exist"
fi
Or:
[ ! -e "$file" ] && echo "file does not exist"
Act on the result of the test being negative (|| instead of &&):
Only:
[ -e "$file" ] || echo "file does not exist"
This looks silly (IMO), don't use it unless your code has to be portable to the Bourne shell (like the /bin/sh of Solaris 10 or earlier) that lacked the pipeline negation operator (!):
if [ -e "$file" ]; then
:
else
echo "file does not exist"
fi
envfile=.env
if [ ! -f "$envfile" ]
then
echo "$envfile does not exist"
exit 1
fi
To reverse a test, use "!".
That is equivalent to the "not" logical operator in other languages. Try this:
if [ ! -f /tmp/foo.txt ];
then
echo "File not found!"
fi
Or written in a slightly different way:
if [ ! -f /tmp/foo.txt ]
then echo "File not found!"
fi
Or you could use:
if ! [ -f /tmp/foo.txt ]
then echo "File not found!"
fi
Or, presing all together:
if ! [ -f /tmp/foo.txt ]; then echo "File not found!"; fi
Which may be written (using then "and" operator: &&) as:
[ ! -f /tmp/foo.txt ] && echo "File not found!"
Which looks shorter like this:
[ -f /tmp/foo.txt ] || echo "File not found!"
The test thing may count too. It worked for me (based on Bash Shell: Check File Exists or Not):
test -e FILENAME && echo "File exists" || echo "File doesn't exist"
This code also working .
#!/bin/bash
FILE=$1
if [ -f $FILE ]; then
echo "File '$FILE' Exists"
else
echo "The File '$FILE' Does Not Exist"
fi
The simplest way
FILE=$1
[ ! -e "${FILE}" ] && echo "does not exist" || echo "exists"
This shell script also works for finding a file in a directory:
echo "enter file"
read -r a
if [ -s /home/trainee02/"$a" ]
then
echo "yes. file is there."
else
echo "sorry. file is not there."
fi
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 $FILE || echo File there!
If you want to use test instead of [], then you can use ! to get the negation:
if ! test "$FILE"; then
echo "does not exist"
fi
You can also group multiple commands in the one liner
[ -f "filename" ] || ( echo test1 && echo test2 && echo test3 )
or
[ -f "filename" ] || { echo test1 && echo test2 && echo test3 ;}
If filename doesn't exit, the output will be
test1
test2
test3
Note: ( ... ) runs in a subshell, { ... ;} runs in the same shell.