The Linux discover command can find information based mostly on nearly any standards that you simply may want. This submit describes the various standards you should utilize to search out what you’re in search of – even when you may’t bear in mind what you named a file or while you final modified it or added content material.
Primary discover syntax
The fundamental syntax for the discover command seems to be like this:
$ discover [starting location] [criteria] [options] [action to take]
The beginning location is usually a listing identify (e.g., /var/log), the present listing (.), your private home listing whether or not you’re sitting in it or not (~), or a listing relative to your present place (e.g., ./bin). You could be as particular as you need when getting into the beginning location.
Discovering information by identify
Looking for information by identify is the simplest and most simple approach to discover a file. Word the command under makes use of an asterisk so that it’ll discover any information that begin with “repair”.
$ discover ~ -name "repair*" -print /residence/shs/fixit
Discovering information by sort
You may as well discover information which are of a selected sort (e.g., a file, listing or symbolic hyperlink) To discover a file, use “-type f”.
$ discover Paperwork -name junk* -type f -print Paperwork/junk.odt Paperwork/junk.docx
To discover a symbolic hyperlink, use “-type l”.
$ discover . -name "h*" -type l -ls
28603 0 lrwxrwxrwx 1 shs shs 9 Jun 27 12:27 ./maintain -> /tmp/hold4me
To discover a listing, use “-type d”.
$ discover . -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 Could 20 2021 ./Footage
3468 4 drwxr-xr-x 2 shs shs 4096 Could 7 2021 ./Movies
Figuring out what you need to see or do
You in all probability seen within the two earlier instructions which you could listing (-ls means a protracted itemizing) or just show the identify of a file (-print). These aren’t the one choices.
To delete a file, you’ll want to add the -exec rm command as proven under. This command will take away any file with a “.previous” extension from your private home listing (together with subdirectories).
$ discover ~ -name *.previous -exec rm {} ;
The exec command may even will let you view the contents of a file. Right here’s an instance:
$ discover . -name "h*" -type l -exec cat {} ;
Meow, Meow!
Discovering information by proprietor and/or group
To seek out information by consumer, embrace the “-user uname” specification. You’ll be able to specify the username or the consumer ID. The third instance under ship output that generates an error (e.g., permission denied) to /dev/null in order that it would not muddle up the display screen.
$ discover . -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
$ discover . -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
$ discover /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
Relying on file permissions, you may have the ability to discover information belonging to different customers as properly.
$ discover /residence -group tom -print /residence/tom /residence/tom/report /residence/tom/myfile
To seek out information by group, use the “-group gname” specification. Group IDs can be utilized instead of group names.
$ discover /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
Discovering information by file permissions
To seek out information which have group write permissions, you would use a command like this one:
$ discover /usr/bin -name "web*" -perm -g=w -ls
26666 0 lrwxrwxrwx 1 root root 24 Feb 14 2021 /usr/bin/netcat -> /and so forth/alternate options/netcat
Discover that the start of the file identify is included or there can be extra information listed.
You may as well search for information by file permissions as within the following instance that appears for information that present all entry (777):
$ discover /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
Discovering information by age
To discover a file by age, use the -mtime possibility and specify the variety of days for the reason that file was modified utilizing a quantity like +100 (greater than 100 days previous) or -10 (modified inside the final 10 days).
$ discover Paperwork -mtime -1 Paperwork Paperwork/junk.doc
Discovering information by dimension
To seek out empty information, use a command like this one:
$ discover . -size 0 -ls | head -1
28959 0 -rw-rw-r-- 1 shs shs 0 Jun 27 13:18 ./.abc
With out the addition of the head command on this instance, this command would discover much more empty information – representing the cache and such.
$ discover . -size 0 -ls | wc -l 45
The subsequent command finds information which are bigger than 1 GB: Discover that the command sends all of the “permission denied” messages to the /dev/null.
$ discover / -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
Earlier posts on the discover command
A few of my earlier posts on the discover command are listed under:
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 discover command has plenty of choices that you should utilize to slim down your search if you end up in search of particular information in your Linux system.
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