303

What's wrong with the following code?

name='$filename | cut -f1 -d'.''

As is, I get the literal string $filename | cut -f1 -d'.', but if I remove the quotes I don't get anything. Meanwhile, typing

"test.exe" | cut -f1 -d'.'

in a shell gives me the output I want, test. I already know $filename has been assigned the right value. What I want to do is assign to a variable the filename without the extension.

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3
  • 20
    basename $filename .exe would do the same thing. That's assuming you always know what extension you want to remove. Commented Aug 28, 2012 at 14:54
  • 15
    @mpe, you mean basename "$filename" .exe. Otherwise filenames with spaces would be bad news. Commented Jun 15, 2016 at 19:35
  • See also Extract substring in Bash where also "${file#prestring}" is explained. Commented May 20, 2022 at 15:43

15 Answers 15

Reset to default
524

You can also use parameter expansion:

$ filename=foo.txt $ echo "${filename%.*}" foo

If you have a filepath and not just a filename, you'll want to use basename first to get just the filename including the extension. Otherwise, if there's a dot only in the path (e.g. path.to/myfile or ./myfile), then it will trim inside the path; even if there isn't a dot in the path, it will get the (e.g. path/to/myfile if the path is path/to/myfile.txt):

$ filepath=path.to/foo.txt $ echo "${filepath%.*}" path.to/foo $ filename=$(basename $filepath) $ echo $filename foo.txt $ echo "${filename%.*}" foo

Just be aware that if the filename only starts with a dot (e.g. .bashrc) it will remove the whole filename.

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11 Comments

here the explanation of the command: gnu.org/software/bash/manual/html_node/…
And here I was about to use echo -n "This.File.Has.Periods.In.It.txt" | awk -F. '{$NF=""; print $0}' | tr ' ' '.' | rev | cut -c 2- | rev. Thanks.
Does this work with files with multiple extensions like image.png.gz?
%.* will only remove the last extension; if you want to remove all the extensions, use %%.*.
Be warned this deletes the entire name if there is no extension and the path is relative. E.g., filename=./ihavenoextension.
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210

If you know the extension, you can use basename

$ basename /home/jsmith/base.wiki .wiki base
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5 Comments

How can I remove just .wiki and end up with /home/jsmith/base?
Update: answer: See stackoverflow.com/a/32584935/4561887. Works perfectly!
this should be the accepted answer in my view
@GabrielStaples you could combine it with dirname, e.g. file=/home/jsmith/base.wiki; echo $(dirname $file)/$(basename $file .wiki)
I went with this. The nice thing is that basename is made for this and I discovered a new capability in what it can do.
179

You should be using the command substitution syntax $(command) when you want to execute a command in script/command.

So your line would be 

name=$(echo "$filename" | cut -f 1 -d '.')

Code explanation:

  1. echo get the value of the variable $filename and send it to standard output
  2. We then grab the output and pipe it to the cut command
  3. The cut will use the . as delimiter (also known as separator) for cutting the string into segments and by -f we select which segment we want to have in output
  4. Then the $() command substitution will get the output and return its value
  5. The returned value will be assigned to the variable named name

Note that this gives the portion of the variable up to the first period .:

$ filename=hello.world $ echo "$filename" | cut -f 1 -d '.' hello $ filename=hello.hello.hello $ echo "$filename" | cut -f 1 -d '.' hello $ filename=hello $ echo "$filename" | cut -f 1 -d '.' hello
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10 Comments

Backticks are deprecated by POSIX, $() is preferred.
Forking and piping to get at a few characters is about the worst solution imaginable.
The problem with this answer is it assumes input string has ONLY one dot ... @chepner below has a much better solution ... name=${filename%.*}
This answer is characteristic of beginners and should not be spreaded. Use the builtin mechanism as described by chepner's answer
Fails on ./ihavenoextension, just like the other answer.
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58

If your filename contains a dot (other than the one of the extension) then use this:

echo $filename | rev | cut -f 2- -d '.' | rev
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8 Comments

I forgot the middle rev, but once I saw it, this was great!
It’s even better with an -s option given to cut, so that it returns an empty string whenever the filename contains no dot.
This should be the accepted answer in my opinion, since it works on path with dots in them, with hidden files starting with a dot, or even with file with multiple extensions.
What happens with a file like this: filename=/tmp.d/foo?
It has problems with "dot files" also. Try with .profile for example.
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45

Using POSIX's built-in only:

#!/usr/bin/env sh path=this.path/with.dots/in.path.name/filename.tar.gz # Get the basedir without external command # by stripping out shortest trailing match of / followed by anything dirname=${path%/*} # Get the basename without external command # by stripping out longest leading match of anything followed by / basename=${path##*/} # Strip uptmost trailing extension only # by stripping out shortest trailing match of dot followed by anything oneextless=${basename%.*}; echo "$oneextless" # Strip all extensions # by stripping out longest trailing match of dot followed by anything noext=${basename%%.*}; echo "$noext" # Printout demo printf %s\\n "$path" "$dirname" "$basename" "$oneextless" "$noext"

Printout demo:

this.path/with.dots/in.path.name/filename.tar.gz this.path/with.dots/in.path.name filename.tar.gz filename.tar filename
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3 Comments

What happens with a path like /home/user/.profile?
@FedKad How about you test it?
For a path like /home/user/.profile the $oneextless and $noext variables become empty strings; in other words the "dot-file" name vanishes.
28 
file1=/tmp/main.one.two.sh t=$(basename "$file1") # output is main.one.two.sh name=$(echo "$file1" | sed -e 's/\.[^.]*$//') # output is /tmp/main.one.two name=$(echo "$t" | sed -e 's/\.[^.]*$//') # output is main.one.two

use whichever you want. Here I assume that last . (dot) followed by text is extension.

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1 Comment

What happens when file1=/tmp.d/mainonetwosh? The sed expression should be replaced with 's/\.[^./]*$//'
8 
#!/bin/bash file=/tmp/foo.bar.gz echo $file ${file%.*}

outputs:

/tmp/foo.bar.gz /tmp/foo.bar

Note that only the last extension is removed.

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1 Comment

What happens with a file like this: file=/tmp.d/foo ?
7

In Zsh:

fullname=bridge.zip echo ${fullname:r}

It's simple, clean and it can be chained to remove more than one extension:

fullname=bridge.tar.gz echo ${fullname:r:r}

And it can be combined with other similar modifiers.

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Comments

4 
#!/bin/bash filename=program.c name=$(basename "$filename" .c) echo "$name"

outputs:

program
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2 Comments

How is this different from the answer given by Steven Penny 3 years ago?
@gniourf_gniourf upvoting because you've made it a useful answer by showing how to correctly use it with a variable.
3

My recommendation is to use basename.
It is by default in Ubuntu, visually simple code and deal with majority of cases.

Here are some sub-cases to deal with spaces and multi-dot/sub-extension:

pathfile="../space fld/space -file.tar.gz" echo ${pathfile//+(*\/|.*)}

It usually get rid of extension from first ., but fail in our .. path

echo **"$(basename "${pathfile%.*}")"** space -file.tar # I believe we needed exatly that

Here is an important note:

I used double quotes inside double quotes to deal with spaces. Single quote will not pass due to texting the $. Bash is unusual and reads "second "first" quotes" due to expansion.

However, you still need to think of .hidden_files

hidden="~/.bashrc" echo "$(basename "${hidden%.*}")" # will produce "~" !!!

not the expected "" outcome. To make it happen use $HOME or /home/user_path/
because again bash is "unusual" and don't expand "~" (search for bash BashPitfalls) 

hidden2="$HOME/.bashrc" ; echo '$(basename "${pathfile%.*}")'
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3

Two problems with your code:

  1. You used a ' (tick) instead of a ` (back tick) to surround the commands that generate the string you want to store in the variable.
  2. You didn't "echo" the variable "$filename" to the pipe into the "cut" command.

I'd change your code to "name=`echo $filename | cut -f 1 -d '.' `", as shown below (again, notice the back ticks surrounding the name variable definition):

$> filename=foo.txt $> echo $filename foo.txt $> name=`echo $filename | cut -f1 -d'.'` $> echo $name foo $>

EDIT: If I can add to the answer, I'd use the $( ... ) construct as opposed to using back ticks. I think it is a whole lot cleaner, and less prone to tick confusion.

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1 Comment

This is the only answer that actually tries to answer the question What's wrong with the following code?
2

Answers provided previously have problems with paths containing dots. Some examples:

/xyz.dir/file.ext ./file.ext /a.b.c/x.ddd.txt

I prefer to use |sed -e 's/\.[^./]*$//'. For example:

$ echo "/xyz.dir/file.ext" | sed -e 's/\.[^./]*$//' /xyz.dir/file $ echo "./file.ext" | sed -e 's/\.[^./]*$//' ./file $ echo "/a.b.c/x.ddd.txt" | sed -e 's/\.[^./]*$//' /a.b.c/x.ddd

Note: If you want to remove multiple extensions (as in the last example), use |sed -e 's/\.[^/]*$//':

$ echo "/a.b.c/x.ddd.txt" | sed -e 's/\.[^/]*$//' /a.b.c/x

However, this method will fail in "dot-files" with no extension:

$ echo "/a.b.c/.profile" | sed -e 's/\.[^./]*$//' /a.b.c/

To cover also such cases, you can use:

$ echo "/a.b.c/.profile" | sed -re 's/(^.*[^/])\.[^./]*$/\1/' /a.b.c/.profile
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2 Comments

Thanks, the only answer that works with ./ihavenoextension!
I took a look at all answers and assuming you have sed available then this seems best, covers all edge cases. Here is a function rm_ext () { sed -re 's/(^.*[^/])\.[^./]*$/\1/' <<< "$1" }
2

This one covers all possibilities! (dot in the path or not; with extension or no extension):

tmp1=${filename##*/};tmp2=${tmp1:1};filename_noextension=$(echo -n ${tmp1:0:1};echo ${tmp2%.*});echo $filename_noextension

Notes:

  • It gives you the filename without any extension. So there is no path in the $filename_noextension variable.
  • You end up with two unwanted variables $tmp1 and $tmp2. Make sure you are not using them in your script.

examples to test:

filename=.bashrc; echo "filename: $filename"; tmp1=${filename##*/};tmp2=${tmp1:1};filename_noextension=$(echo -n ${tmp1:0:1};echo ${tmp2%.*}); echo "filename without extension: $filename_noextension"

filename=.bashrc.txt; echo "filename: $filename"; tmp1=${filename##*/};tmp2=${tmp1:1};filename_noextension=$(echo -n ${tmp1:0:1};echo ${tmp2%.*}); echo "filename without extension: $filename_noextension"

filename=.bashrc.txt.tar; echo "filename: $filename"; tmp1=${filename##*/};tmp2=${tmp1:1};filename_noextension=$(echo -n ${tmp1:0:1};echo ${tmp2%.*}); echo "filename without extension: $filename_noextension"

filename=~/.bashrc; echo "filename: $filename"; tmp1=${filename##*/};tmp2=${tmp1:1};filename_noextension=$(echo -n ${tmp1:0:1};echo ${tmp2%.*}); echo "filename without extension: $filename_noextension"

filename=~/.bashrc.txt.tar; echo "filename: $filename"; tmp1=${filename##*/};tmp2=${tmp1:1};filename_noextension=$(echo -n ${tmp1:0:1};echo ${tmp2%.*}); echo "filename without extension: $filename_noextension"

filename=bashrc; echo "filename: $filename"; tmp1=${filename##*/};tmp2=${tmp1:1};filename_noextension=$(echo -n ${tmp1:0:1};echo ${tmp2%.*}); echo "filename without extension: $filename_noextension"

filename=bashrc.txt; echo "filename: $filename"; tmp1=${filename##*/};tmp2=${tmp1:1};filename_noextension=$(echo -n ${tmp1:0:1};echo ${tmp2%.*}); echo "filename without extension: $filename_noextension"

filename=bashrc.txt.tar; echo "filename: $filename"; tmp1=${filename##*/};tmp2=${tmp1:1};filename_noextension=$(echo -n ${tmp1:0:1};echo ${tmp2%.*}); echo "filename without extension: $filename_noextension"

filename=~/bashrc; echo "filename: $filename"; tmp1=${filename##*/};tmp2=${tmp1:1};filename_noextension=$(echo -n ${tmp1:0:1};echo ${tmp2%.*}); echo "filename without extension: $filename_noextension"

filename=~/bashrc.txt.tar; echo "filename: $filename"; tmp1=${filename##*/};tmp2=${tmp1:1};filename_noextension=$(echo -n ${tmp1:0:1};echo ${tmp2%.*}); echo "filename without extension: $filename_noextension"

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Comments

1

As pointed out by Hawker65 in the comment of chepner answer, the most voted solution does neither take care of multiple extensions (such as filename.tar.gz), nor of dots in the rest of the path (such as this.path/with.dots/in.path.name). A possible solution is:

a=this.path/with.dots/in.path.name/filename.tar.gz echo $(dirname $a)/$(basename $a | cut -d. -f1)
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2 Comments

This one strips "tar.gz" by selecting characters before the first instance of a dot in the filename not counting the path. One probably doesn't want to strip extensions that way.
If you know it ends in .tar.gz, you can just use $(basename "$a" .tar.gz). Also, make sure to wrap your variable in quotes everywhere if there's any chance it will contain spaces or other weird characters!
0

After trying several solutions that didn't work for dot files, here is my Bash compatible unelegant solution.

# Given a file path, return only the file name, stripped of its extension. basefilename() { filename="$(basename "$1")" prefix= if [[ ${filename::1} == . ]]; then prefix=. filename="${filename:1}" fi echo -n "$prefix" echo "$filename" | rev | cut -f 2- -d '.' | rev }

I tested it only on a few cases though. Let me know if you have some improvements.

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