Linux Basics: A gentle introduction to 'find'

#1 April 18, 2009

This guide has been converted to a wiki:

https://help.ubuntu.com/community/find

Support is still available in this thread so feel free to ask any questions :).

#2 May 1, 2009

Yet another excellent guide. Good job, Andrew.

#3 May 1, 2009

Nice guide... can you add searching within files? For example, there are a number of documents in a given directory. You want to find a keyword within them.

#4 May 1, 2009

Hi FakeOutdoorsman,

FakeOutdoorsman said: Yet another excellent guide. Good job, Andrew.

Thanks very much! I plan about a dozen of these in a series, partly because it fills a need and partly because with vdpau, FFmpeg-mt, PPA archives, impending rc3 release etc I will be slipping out of the MPlayer business soon :-).

Andrew

#5 May 1, 2009

Hi graysky,

graysky said: Nice guide... can you add searching within files? For example, there are a number of documents in a given directory. You want to find a keyword within them.

There is an immense amount of material omitted in this guide, in part because this is intended to be an *introduction* only. But definitely I shall consider adding something like this in the near future. A 'real world' example of the usage of grep that you mentioned could be in my case finding all of the html files that mention 'slrn' in my offline website:


$ **[COLOR="Red"]find $HOME/html/andrews-corner -exec grep -q 'slrn' '{}' \; -print[/COLOR]**
/home/andrew/html/andrews-corner/leafnode.html
/home/andrew/html/andrews-corner/index.html
/home/andrew/html/andrews-corner/slrn.html
/home/andrew/html/andrews-corner/custom_os.patch
/home/andrew/html/andrews-corner/mutt.html

Fantastic program!!

Andrew

#6 May 3, 2009

Very cool.

How can I add an alias to my ~/.bashrc that will allow me to do this on the shell just by typing the alias and word or phrase?

For example, the alias might be called [color=blue]lookfor[/color] and what comes after that could be what you wanna search for inside the files in the current directory.

Example:

$ lookfor lsrn

That would then do this:

find ./ -exec grep -q 'slrn' '{}' \; -print

How can I do that?

Also, how would you handle a group of words?

#7 May 3, 2009

Hi graysky,

graysky said:

How can I add an alias to my ~/.bashrc that will allow me to do this on the shell just by typing the alias and word or phrase?

An interesting question, and one that I had to do a little research on before I could answer properly :-). An actual *alias* would not do as bash aliases are not really meant to contain variables. What you ask for can be set as a bash *function* instead:


lookfor() {
  find . -exec grep -q "$1" '{}' \; -print 
}

This would search the working directory and subdirectories with the syntax:

lookfor search_term

which is what you specified. However a better idea would be to use two variables, the first being the path to search and the second being the search term:

lookfor() {
  find "$1" -exec grep -q "$2" '{}' \; -print 
}

and the syntax would then be:

lookfor path search_term

Place this in ~/.bashrc and have a play with it. Mind you this starts moving towards a shell script which would of course be much more flexible.

Also, how would you handle a group of words?

I am not entirely sure what you mean there, although I sense that your needs are slipping further away from 'find' and leaning more towards grep :-). In fact perhaps a simpler search with 'find' piped to grep would be better. Can you provide a specific example of what you need?

All the best,

Andrew

#8 May 4, 2009

Superb guide, its really very helpful for me, Thanks andrew for sharing with us.

#9 May 5, 2009

Hi paulstephen4,

paulstephen4 said: Superb guide, its really very helpful for me, Thanks andrew for sharing with us.

Thank you *very* much for your kind words,

Andrew

#10 July 27, 2009

Thank you for a clear and concise intro guide. I have been weening myself off of gui now that I built a home server and appreciate this type of reference material.

#11 July 28, 2009

Hi Slowspeed,

Slowspeed said: Thank you for a clear and concise intro guide. I have been weening myself off of gui now that I built a home server and appreciate this type of reference material.

It is totally my pleasure :-). I am in the process of rewriting and expanding this material for the Ubuntu Community Wiki at the moment:

find - Community Documentation https://help.ubuntu.com/community/find

About another week of work to go on that one yet...

Andrew

#12 February 1, 2010

I think this is an understated guide. Passing the results of *find* to other utilities just creates so many possibilities.

#13 April 9, 2012

This guide has been converted to a wiki:

https://help.ubuntu.com/community/find

Support is still available in this thread so feel free to ask any questions :).

#14 April 9, 2012

Heh, thanks for this one :) I've never used find for anything other than searching by file names! (until now)

#15 April 9, 2012

rainbowcats said: Heh, thanks for this one :) I've never used find for anything other than searching by file names! (until now)

Glad to hear the wiki has been useful to you :).

#16 April 9, 2012

Off topic, but I'm up for an awk primer. Fantastic find guide. I'm glad its being promoted again.

#17 April 9, 2012

kevdog said: Off topic, but I'm up for an awk primer. Fantastic find guide. I'm glad its being promoted again.

Well, actually this guide was turned into a wiki a while back but I have just now altered the guide in line with the new way of doing things :). As for an awk primer, I wish I had this knowledge!!

#18 April 17, 2012

Support is still available in this thread so feel free to ask any questions :smile:.Just noticed this thread when reading through the changes to Tutorials and Tips.

Maybe this is more of a shell-scripting question, but here goes: I have a script "newest.sh" in ~/bin that looks like

format='%T@\t%s\t%Tx %TH:%TM:%TS\t%p\n';
find $* -printf "$format" | sort -k1n|cut -f2-

For example: typing

newest.sh . -iname \*.pdf

find: paths must precede expression: file.pdf

Thanks for any help.

#19 April 17, 2012

Oddly enough I cannot duplicate this error:


andrew@skamandros~/media/YouTube$ **[COLOR="Red"]newest.sh [/COLOR]**
17981740	05/28/2009 01:42:49.0000000000	./Armistice_Day_1920_Homecoming_Of_An_Unknown_Warrior2.flv
44465312	09/04/2009 09:45:32.0000000000	./Ruttie_Jinnah.flv
19841820	03/23/2010 11:15:28.0000000000	./Cold_Chisel_Bow_River.mp4
20235169	04/28/2010 17:55:55.0000000000	./ashtanga_yoga_demo.mp4
438626221	12/02/2010 12:00:58.0000000000	./The_Art_Of_Piano_Great_Pianists_Of_The_20Th_Century.flv
475711968	12/23/2010 23:59:27.0000000000	./Gary_Yourofsky.flv
12730971	02/23/2011 14:17:30.0000000000	./Zenga_Zenga.flv
93765772	08/03/2011 07:06:54.0000000000	./Dr_Swami_Shankardev_Rotation_Through_Chakras_Guided_Meditation.mp4
79	12/13/2011 18:42:44.0000000000	./template
0	04/18/2012 08:42:19.3180826960	./file.pdf
4096	04/18/2012 08:42:19.3180826960	.
andrew@skamandros~/media/YouTube$ **[COLOR="Red"]newest.sh . -iname \*.pdf[/COLOR]**
0	04/18/2012 08:42:19.3180826960	./file.pdf

So I have to admit that I am not entirely sure what is happening here...

#20 April 17, 2012

George Heine said:

[...]

For example: typing

newest.sh . -iname \*.pdf

find: paths must precede expression: file.pdf

Thanks for any help.

The problem here is not '-iname', but the stripping of the backslash from the shell, causing the unwanted expansion of '*.pdf' after find's '-iname' option, and the command line would have looked like:

find . -iname file.pdf other_file.pdf ...

#!/bin/bash
set -x

format="%T@\t%s\t%Tx %TH:%TM:%TS\t%p\n"

find "$@" -printf "$format" | sort -k1n | cut -f2-

...
arr=("$@")

find "${arr[@]}" -printf "$format" | sort -k1n | cut -f2-

./newest.sh . -iname "*.pdf"

./newest.sh "dir with space/" -iname "*.pdf" -type f

#21 April 18, 2012

Thanks, erind, for a clear and concise explanation. Tried both your examples and they both worked. Any reason to prefer one over the other?

#22 April 18, 2012

Although in this case the first option ("$@") is simpler, with arrays I've noticed an easier handling of individual tokens, as far as shell quoting is concerned. This quote from *mywiki.wooledge.org* nicely sums it up:

Arrays are basically indexed lists of strings. They are very convenient for their ability to store multiple strings together without relying on a delimiter to split them apart (which is tedious when done correctly and error-prone when not).From: http://mywiki.wooledge.org/BashGuide/Parameters

#23 May 8, 2012

has anyone mentioned that there is a typo in the very first line? two within within's

#24 August 9, 2012

i am confused by the following part of that wiki

It is important to get into the habit of quoting patterns in your search as seen above or your search results can be a little unpredictable. Such a search can be much more sophisticated though. For example if you wished to search for all of the ogg files in your home directory, some of which you think might be named 'OGG' rather than 'ogg', you would run:

find $HOME -iname '*.ogg'

Here the option '-iname' performs a case-insensitive search while the wildcard character '*' matches any character, or number of characters, or zero characters. so in this particular case does it matters to use -name or -iname if we were to search for all files that are .ogg or .OGG ?

i mean we are using the * doesnt that means 'anything' [case or type of char doesnt matter ?] or is the iname for the .ogg there to make that case insensitive ?

thanks ... i would recomend this note/tip to be added to that great wiki..

#25 August 9, 2012

The 'iname' bit allows the search to be case-insensitive (thus matching either 'ogg' or 'OGG'. The '*' operator allows any text that comes before the '.ogg' bit. The two are exclusive, though. Let's say you have two files called 'file.ogg' and 'file.OGG'. If you search by:

find $HOME -name '*.ogg'

You'll only get 'file.ogg' as a result. If you use -iname, though, you'll get both files as a result, because now the search doesn't care about upper or lowercase file names. Does that make more sense?

#26 August 9, 2012

^^ thanks ... on first read i got the impression that it wont matter to use either iname or name and so were two of my collegues.. we were mistaken by the * .. whearas the .ogg is also a part of the search pattern..

thanks again ..

#27 August 12, 2012

chickenPie4breakfast said: has anyone mentioned that there is a typo in the very first line? two within within's

I have corrected this small blunder :).

#28 July 12, 2013

I'm looking to be able to find a bunch of pdfs, move those pdfs to another directory, keep the directory structure, and remove the previous structures. So far I have been able to use the find command and copy the files while keeping the structure:

find /home/john/books1/ -regex ".*$pdf\|epub\|mobi$$" -type f -exec cp '{}' /home/john/temp/ ';'

but if I use mv I get all the files in one directory...

find /home/john/books1/ -regex ".*$pdf\|epub\|mobi$$" -type f -exec mv -b '{}' /home/john/temp/ ';'

Am I stuck using 'cp'? Which is fine, I just need to find a way to then delete them...

find /home/john/books1/ -regex ".*$pdf\|epub\|mobi$$" -type f -exec rm '{}' /home/john/temp/ ';'

I plan to also have this in a cron job but that shouldn't be a problem once I have figured out the script

Thanks for any help :)