find

All posts tagged find

(Copied all these from https://www.binarytides.com/linux-find-command-examples/)

1. List all files in current and subdirectories

This command lists out all the files in the current directory as well as the subdirectories in the current directory.

The command is same as the following

2. Search specific directory or path

The following command will look for files in the test directory in the current directory. Lists out all files by default.

The following command searches for files by their name.

We can also use wildcards

Note that all subdirectories are searched recursively. So this is a very powerful way to find all files of a given extension.

Trying to search the “/” directory which is the root, would search the entire file system including mounted devices and network storage devices. So be careful. Of course, you can press Ctrl + c anytime to stop the command.

Ignore the case

It is often useful to ignore the case when searching for file names. To ignore the case, just use the “iname” option instead of the “name” option.

3. Limit depth of directory traversal

The find command by default travels down the entire directory tree recursively, which is time and resource consuming. However, the depth of directory traversal can be specified. For example, we don’t want to go more than 2 or 3 levels down in the subdirectories. This is done using the maxdepth option.

The second example uses maxdepth of 1, which means it will not go lower than 1 level deep, either only in the current directory.

This is very useful when we want to do a limited search only in the current directory or max 1 level deep subdirectories and not the entire directory tree which would take more time.

Just like maxdepth there is an option called mindepth which does what the name suggests, that is, it will go at least N level deep before searching for the files.

4. Invert match

It is also possible to search for files that do no match a given name or pattern. This is helpful when we know which files to exclude from the search.

So in the above example, we found all files that do not have the extension of php, either non-php files. The find command also supports the exclamation mark inplace of not.

5. Combine multiple search criteria

It is possible to use multiple criteria when specifying name and inverting. For example

The above find command looks for files that begin with abc in their names and do not have a php extension. This is an example of how powerful search expressions can be built with the find command.

OR operator

When using multiple name criteria, the find command would combine them with AND operator, which means that only those files which satisfy all criteria will be matched. However, if we need to perform an OR based matching then the find command has the “o” switch.

The above command search for files ending in either the php extension or the txt extension.

6. Search only files or only directories

Sometimes we want to find only files or only directories with a given name. Find can do this easily as well.

Quite useful and handy!

7. Search multiple directories together

So let’s say you want to search inside 2 separate directories. Again, the command is very simple

Check, that it listed files from 2 separate directories.

8. Find hidden files

Hidden files on Linux begin with a period. So its easy to mention that in the name criteria and list all hidden files.

9. Find files with certain permissions

The find command can be used to find files with a specific permission using the “perm” option. The following command searches for files with the permission 0664

This can be useful to find files with wrong permissions which can lead to security issues. Inversion can also be applied to permission checking.

10. Find files with sgid/suid bits set

The “perm” option of find command accepts the same mode string like chmod. The following command finds all files with permission 644 and sgid bit set.

Similarly, use 1664 for sticky bit. The perm option also supports using an alternative syntax instead of octal numbers.

Note that the “2>/dev/null” removes those entries that have an error of “Permission Denied”

11. Find readonly files

Find all Read Only files.

12. Find executable files

The following command will find executable files

13. Find files owned by particular user

To find all or single file called tecmint.txt under /root directory of owner root.

We could also specify the name of the file or any name related criteria along with user criteria

It’s very easy to see, how we can build up criteria after criteria to narrow down our search for matching files.

14. Search files belonging to group

Find all files that belong to a particular group.

Did you know you could search your home directory by using the ~ symbol?

Easy!!

Search file and directories based on modification date and time

Another great search criteria that the find command supports is a modification and accessed date/times. This is very handy when we want to find out which files were modified as a certain time or date range. Let’s take a few examples

15. Find files modified N days back

To find all the files which are modified 50 days back.

16. Find files accessed in last N days

Find all files that were accessed in the last 50 days.

17. Find files modified in a range of days

Find all files that were modified between 50 to 100 days ago.

18. Find files changed in last N minutes.

Find files modified within the last 1 hour.

19. Files modified in last hour

To find all the files which are modified in last 1 hour.

20. Find Accessed Files in Last 1 Hour

To find all the files which are accessed in last 1 hour.

21. Find files of given size

Search files and directories based on size. To find all 50MB files, use.

22. Find files in a size range

To find all the files which are greater than 50MB and less than 100MB.

23. Find largest and smallest files

The find command, when used in combination with the ls and sort command, can be used to list out the largest files.
The following command will display the 5 largest file in the current directory and its subdirectory. This may take a while to execute depending on the total number of files the command has to process.

Similarly when sorted in ascending order, it would show the smallest files first

24. Find empty files and directories

The following command uses the “empty” option of the find command, which finds all files that are empty.

To file all empty directories use the type “d”.

Really very simple and easy

Some advanced operations

The find command not only finds files based on certain criteria, it can also act upon those files using any Linux command. For example, we might want to delete some files.

Here are some quick examples

25. List out the found files

Let’s say we found files using find command, and now want to list them out as the ls command would have done. This is very easy.

26. Delete all matching files or directories

The following command will remove all text files in the tmp directory.

The same operating can be carried out with directories, just put type d, instead of type f.

Let’s take another example where we want to delete files larger than 100MB

(pulled from http://www.folkstalk.com/2011/12/101-examples-of-using-find-command-in.html)

Find Command in Unix and Linux Examples

Find is one of the powerful utility of Unix (or Linux) used for searching the files in a directory hierarchy. The syntax of find command is

Let see some practical exercises on using find command.

1. How to run the last executed find command?

This will execute the last find command. It also displays the last find command executed along with the result on the terminal.

2. How to find for a file using name?

This will find all the files with name “sum.java” in the current directory and sub-directories.

3. How to find for files using name and ignoring case?

This will find all the files with name “sum.java” while ignoring the case in the current directory and sub-directories.

4. How to find for a file in the current directory only?

This will find for the file “sum.java” in the current directory only

5. How to find for files containing a specific word in its name?

It displayed all the files which have the word “java” in the filename

6. How to find for files in a specific directory?

This will look for the files in the /etc directory with “java” in the filename

7. How to find the files whose name are not “sum.java”?

This is like inverting the match. It prints all the files except the given file “sum.java”.

8. How to limit the file searches to specific directories?

You can see here the find command displayed all the files with name “sum.java” in the current directory and sub-directories.

a. How to print the files in the current directory and one level down to the current directory?

b. How to print the files in the current directory and two levels down to the current directory?

c. How to print the files in the subdirectories between level 1 and 4?

9. How to find the empty files in a directory?

10. How to find the largest file in the current directory and sub directories

The find command “find . -type f -exec ls -s {} \;” will list all the files along with the size of the file. Then the sort command will sort the files based on the size. The head command will pick only the first line from the output of sort.

11. How to find the smallest file in the current directory and sub directories

Another method using find is

12. How to find files based on the file type?

a. Finding socket files

b. Finding directories

c. Finding hidden directories

d. Finding regular files

e. Finding hidden files

13. How to find files based on the size?

a. Finding files whose size is exactly 10M

b. Finding files larger than 10M size

c. Finding files smaller than 10M size

14. How to find the files which are modified after the modification of a give file.

This will display all the files which are modified after the file “sum.java”

15. Display the files which are accessed after the modification of a give file.

16. Display the files which are changed after the modification of a give file.

17. How to find the files based on the file permissions?

This will display the files which have read, write, and execute permissions. To know the permissions of files and directories use the command “ls -l”.

18. Find the files which are modified within 30 minutes.

19. Find the files which are modified within 1 day.

20. How to find the files which are modified 30 minutes back

21. How to find the files which are modified 1 day back.

22. Print the files which are accessed within 1 hour.

23. Print the files which are accessed within 1 day.

24. Display the files which are changed within 2 hours.

25. Display the files which are changed within 2 days.

26. How to find the files which are created between two files.

So far we have just find the files and displayed on the terminal. Now we will see how to perform some operations on the files.

27.  How to find the permissions of the files which contain the name “java”?

Alternate method is

28.  Find the files which have the name “java” in it and then display only the files which have “class” word in them?

29.  How to remove files which contain the name “java”.