How to Delete All Files in a Folder Except Certain Extensions

Bywiredgorilla

Sometimes, you may find yourself in a situation where you need to delete all files in a directory or simply clean up a directory by removing all files except those with a specific extension (e.g., files ending with a particular type).

In this article, we will show you how to delete files in a directory, excluding certain file extensions or types, using the rm, find, and globignore commands.

Before we move any further, let us start by briefly having a look at one important concept in Linux – filename pattern matching, which will enable us to deal with our issue at hand.

In Linux, a shell pattern is a string that consists of the following special characters, known as wildcards or metacharacters:

  • * – matches zero or more characters
  • ? – matches any single character
  • [seq] – matches any character in seq
  • [!seq] – matches any character not in seq

There are three possible methods we shall explore here, and these include:

Delete Files Using Extended Pattern Matching Operators

The extended pattern matching operators are listed below. In this case, pattern-list refers to one or more filenames, separated using the | character:

  • *(pattern-list) – matches zero or more occurrences of the specified patterns
  • ?(pattern-list) – matches zero or one occurrence of the specified patterns
  • +(pattern-list) – matches one or more occurrences of the specified patterns
  • @(pattern-list) – matches one of the specified patterns
  • !(pattern-list) – matches anything except one of the given patterns

To use them, enable the extglob shell option as follows:

shopt -s extglob

1. To delete all files in a directory except a specific file, type the following command:

rm -v !("filename")
Delete All Files Except One File in Linux
Delete All Files Except One File in Linux

2. To delete all files with the exception of filename1 and filename2:

rm -v !("filename1"|"filename2")
Delete All Files Except Few Files in Linux
Delete All Files Except a Few Files in Linux

3. To remove all files except for .zip files, interactively:

rm -i !(*.zip)
Delete All Files Except Zip Files in Linux
Delete All Files Except Zip Files in Linux

4. To delete all files except for .zip and .odt files while displaying the actions being performed:

rm -v !(*.zip|*.odt)
Delete All Files Except Certain File Extensions
Delete All Files Except Certain File Extensions

Once you have all the required commands, turn off the extglob shell option like so:

shopt -u extglob

Delete Files Using Linux find Command

Under this method, we can use find command exclusively with appropriate options or in conjunction with the xargs command by employing a pipeline as in the forms below:

find /directory/ -type f -not -name 'PATTERN' -delete
find /directory/ -type f -not -name 'PATTERN' -print0 | xargs -0 -I {} rm {}
find /directory/ -type f -not -name 'PATTERN' -print0 | xargs -0 -I {} rm [options] {}

5. The following command will delete all files apart from .gz files in the current directory:

find . -type f -not -name '*.gz'-delete
Command find - Remove All Files Except .gz Files
Command find – Remove All Files Except .gz Files

6. Using a pipeline and xargs, you can modify the case above as follows:

find . -type f -not -name '*gz' -print0 | xargs -0  -I {} rm -v {}
Remove Files Using find and xargs Commands
Remove Files Using find and xargs Commands

7. Let us look at one additional example, the command below will wipe out all files excluding .gz, .odt, and .jpg files in the current directory:

find . -type f -not (-name '*gz' -or -name '*odt' -or -name '*.jpg' ) -delete
Remove All Files Except File Extensions
Remove All Files Except File Extensions

Delete Files Using Bash GLOBIGNORE Variable

This last approach, however, only works with bash. Here, the GLOBIGNORE variable stores a colon-separated pattern-list (filenames) to be ignored by pathname expansion.

To employ this method, move into the directory that you wish to clean up, then set the GLOBIGNORE variable as follows:

cd test
GLOBIGNORE=*.odt:*.iso:*.txt

In this instance, all files other than .odt, .iso, and .txt files with be removed from the current directory.

Now run the command to clean up the directory:

rm -v *

Afterwards, turn off GLOBIGNORE variable:

$ unset GLOBIGNORE
Delete Files Using Bash GLOBIGNORE Variable
Delete Files Using Bash GLOBIGNORE Variable

Note: To understand the meaning of the flags employed in the commands above, refer to the man pages of each command we have used in the various illustrations.

Conclusion

These are a few simple and effective ways to delete files in Linux, keeping only those with specific extensions or filenames intact. If you know of any other useful command-line techniques for cleaning up directories, feel free to share them in the feedback section below.

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