The Linux find command can locate files based on almost any criteria that you might need. This post describes the many criteria you can use to find what you’re looking for – even when you can’t remember what you named a file or when you last changed it or added content.
Basic find syntax
The basic syntax for the find command looks like this:
$ find [starting location] [criteria] [options] [action to take]
The starting location can be a directory name (e.g., /var/log), the current directory (.), your home directory whether you’re sitting in it or not (~), or a directory relative to your current position (e.g., ./bin). You can be as specific as you want when entering the starting location.
Finding files by name
Searching for files by name is the easiest and most straightforward way to find a file. Note the command below uses an asterisk so that it will find any files that start with “fix”.
$ find ~ -name "fix*" -print /home/shs/fixit
Finding files by type
You can also find files that are of a specific type (e.g., a file, directory or symbolic link) To find a file, use “-type f”.
$ find Documents -name junk* -type f -print Documents/junk.odt Documents/junk.docx
To find a symbolic link, use “-type l”.
$ find . -name "h*" -type l -ls
28603 0 lrwxrwxrwx 1 shs shs 9 Jun 27 12:27 ./hold -> /tmp/hold4me
To find a directory, use “-type d”.
$ find . -type d -ls | head -3
3389 4 drwxr-x--- 25 shs shs 4096 Jun 27 14:24 .
3467 4 drwxr-xr-x 2 shs shs 4096 May 20 2021 ./Pictures
3468 4 drwxr-xr-x 2 shs shs 4096 May 7 2021 ./Videos
Determining what you want to see or do
You probably noticed in the two previous commands that you can list (-ls means a long listing) or simply display the name of a file (-print). These are not the only options.
To delete a file, you need to add the -exec rm command as shown below. This command will remove any file with a “.old” extension from your home directory (including subdirectories).
$ find ~ -name *.old -exec rm {} ;
The exec command can even allow you to view the contents of a file. Here’s an example:
$ find . -name "h*" -type l -exec cat {} ;
Meow, Meow!
Finding files by owner and/or group
To find files by user, include the “-user uname” specification. You can specify the username or the user ID. The third example below send output that generates an error (e.g., permission denied) to /dev/null so that it doesn’t clutter up the screen.
$ find . -user shs -ls | head -4
3389 4 drwxr-x--- 25 shs shs 4096 Jun 27 13:18 .
5617 4 -rw-rw-r-- 1 shs shs 22 Feb 15 2021 ./CHECKME
8001 4 -rwx------ 1 shs shs 150 Feb 25 2021 ./send_msg
12727 24 -rw-rw-r-- 1 shs shs 20805 Apr 15 2021 ./history-rece
$ find . -user 1000 -ls | head -4
3389 4 drwxr-x--- 25 shs shs 4096 Jun 27 13:18 .
5617 4 -rw-rw-r-- 1 shs shs 22 Feb 15 2021 ./CHECKME
8001 4 -rwx------ 1 shs shs 150 Feb 25 2021 ./send_msg
12727 24 -rw-rw-r-- 1 shs shs 20805 Apr 15 2021 ./history-recent
$ find /tmp -user shs -ls 2> /dev/null
26476575 4 -rw-rw-r-- 1 shs shs 10 Jun 27 12:44 /tmp/haha
26476577 4 drwx------ 2 shs shs 4096 Jun 27 12:09 /tmp/tree
26476585 0 srwxrwxrwx 1 shs shs 0 Jun 27 12:09 /tmp/dbus
26476595 4 -r--r--r-- 1 shs shs 11 Jun 27 12:09 /tmp/.X1-lock
Depending on file permissions, you might be able to find files belonging to other users as well.
$ find /home -group tom -print /home/tom /home/tom/report /home/tom/myfile
To find files by group, use the “-group gname” specification. Group IDs can be used in place of group names.
$ find /tmp -group 1000 -ls 2>/dev/null 26476575 4 -rw-rw-r-- 1 shs shs 10 Jun 27 12:44 /tmp/haha 26476577 4 drwx------ 2 shs shs 4096 Jun 27 12:09 /tmp/tracker-extract-files.1000 26476585 0 srwxrwxrwx 1 shs shs 0 Jun 27 12:09 /tmp/dbus-HpFApADlMO 26476595 4 -r--r--r-- 1 shs shs 11 Jun 27 12:09 /tmp/.X1-lock 26476580 0 srwxrwxrwx 1 shs shs 0 Jun 27 12:09 /tmp/.ICE-unix/2051 26476596 0 srwxrwxr-x 1 shs shs 0 Jun 27 12:09 /tmp/.X11-unix/X1 26476594 0 srwxrwxr-x 1 shs shs 0 Jun 27 12:09 /tmp/.X11-unix/X0 26476586 4 -r--r--r-- 1 shs shs 11 Jun 27 12:09 /tmp/.X0-lock
Finding files by file permissions
To find files that have group write permissions, you could use a command like this one:
$ find /usr/bin -name "net*" -perm -g=w -ls
26666 0 lrwxrwxrwx 1 root root 24 Feb 14 2021 /usr/bin/netcat -> /etc/alternatives/netcat
Notice that the beginning of the file name is included or there would be more files listed.
You can also look for files by file permissions as in the following example that looks for files that provide all access (777):
$ find /usr/bin -name "d*" -perm 777 -ls | head -3
34026 0 lrwxrwxrwx 1 root root 9 Mar 12 2021 /usr/bin/dvipdfmx -> xdvipdfmx
29934 0 lrwxrwxrwx 1 root root 18 Jan 29 2021 /usr/bin/distro-info -> ubuntu-distro-info
33159 0 lrwxrwxrwx 1 root root 6 Feb 17 2021 /usr/bin/dvilualatex -> luatex
Finding files by age
To find a file by age, use the -mtime option and specify the number of days since the file was modified using a number like +100 (more than 100 days old) or -10 (modified within the last 10 days).
$ find Documents -mtime -1 Documents Documents/junk.doc
Finding files by size
To find empty files, use a command like this one:
$ find . -size 0 -ls | head -1
28959 0 -rw-rw-r-- 1 shs shs 0 Jun 27 13:18 ./.abc
Without the addition of the head command in this example, this command would find a lot more empty files – representing the cache and such.
$ find . -size 0 -ls | wc -l 45
The next command finds files that are larger than 1 GB: Notice that the command sends all the “permission denied” messages to the /dev/null.
$ find / -type f -size +1G -ls 2>/dev/null 12 2097156 -rw------- 1 root root 2147483648 Feb 14 2021 /swapfile 18 8388612 -rw------- 1 root root 8589934592 Sep 9 2021 /mint/swapfile/40265
Previous posts on the find command
Some of my earlier posts on the find command are listed below:
https://www.networkworld.com/article/3527420/how-to-find-what-you-re-looking-for-on-linux-with-find.html https://www.networkworld.com/article/3233305/using-the-linux-find-command-with-caution.html
Wrap-up
The find command has a lot of options that you can use to narrow down your search when you are looking for specific files on your Linux system.
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