Linux / UNIX: Finding and locating files with find command part # 2

by on July 23, 2005 · 12 comments· LAST UPDATED August 24, 2007

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In the first part we talked about find command basic usage.

Now let us see how to use find command
(a) To gain lots of useful information about users and their files

(b) Monitor and enhance the security of system using find command

Finding all set user id files

setuid ("suid") and setgid are access right flags that can be assigned to files and directories on a Unix based operating system. They are mostly used to allow users on a computer system to execute binary executables with temporarily elevated privileges in order to perform a specific task.
# find / -perm +u=s
OR
# find / -perm +4000

See also, shell script to find all programs and scripts with setuid set on.

Finding all set group id files

# find / -perm +g=s
OR
# find / -perm +2000

See also, shell script to find all programs and scripts with setgid bit set on.

Finding all large directories

To find all directories taking 50k (kilobytes) blocks of space. This is useful to find out which directories on system taking lot of space.
# find / -type d -size +50k
Output:

/var/lib/dpkg/info
/var/log/ksymoops
/usr/share/doc/HOWTO/en-html
/usr/share/man/man3

Finding all large files on a Linux / UNIX

# find / -type f -size +20000k
Output:

var/log/kern.log
/sys/devices/pci0000:00/0000:00:02.0/resource0
/sys/devices/pci0000:00/0000:00:00.0/resource0
/opt/03Jun05/firefox-1.0.4-source.tar.bz2

However my favorite hack to above command is as follows:
# find / -type f -size +20000k -exec ls -lh {} \; | awk '{ print $8 ": " $5 }'

/var/log/kern.log: 22M
/sys/devices/pci0000:00/0000:00:02.0/resource0: 128M
/sys/devices/pci0000:00/0000:00:00.0/resource0: 256M
/opt/03Jun05/firefox-1.0.4-source.tar.bz2: 32M

Above command will find all files block size greater than 20000k and print filename followed by the file size. Output is more informative as compare to normal find command output :D

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{ 12 comments… read them below or add one }

1 Axxs January 26, 2006 at 7:48 am

the last hack there is a nice one .. great having sizes show :)

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2 Sharjeel August 8, 2006 at 7:05 pm

The last hack for finding large files should be as follows

find / -type f -size +100000k -exec ls -lh {} ; | awk ‘{ print $9 “: ” $5 }’


Sharjeel
http://www.sharjeel.net

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3 JeffB December 6, 2006 at 10:40 am

Thanks a bunch, that command string was just what I was looking for, and I had looked at around 20 other sites with nothing near as good. (As Sharjeel said $9 is the filename, at least on my system.)

To tweak the output and have the file sizes in a column, add this to the end:

| column -t

this just expands the tabs to even the columns out.

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4 Diesel January 2, 2007 at 8:11 pm

Thank you very much for this snip!!! I was looking all over for something this small and simple to tell me what I needed to know in a clear manner!

Thanks Again!

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5 William Bequette August 12, 2007 at 3:39 pm

Very nice little piece of info.
Is there a way to escape file name spaces?
Output stops with colon at first win file name space for each file found.
Thanks FnG

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6 Valter February 26, 2008 at 7:06 pm

In my system I had to remove the k from the size to work.

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7 Aaron December 5, 2008 at 4:42 pm

Valter, you are probably using HP-UX which does not accept (…+20000k) k for the size to work

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8 jagadeesh January 21, 2009 at 1:41 pm

how to redirect the running log file info to other file

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9 kashyap December 22, 2010 at 5:57 am

How to exlude a directory while executing the find command

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10 Dotcode March 7, 2011 at 4:26 pm

i have tried to write a bash script for linux that would tell us the largest file in a folder.
someone who can should help me. tanks

Reply

11 Patrick December 21, 2011 at 7:53 am

The find command for setuid files isnt that useful. Almost never is the setuid bit the only bit set. The better way is
# find / -perm -u=s
or
# find / -perm -4000

Those will find any files with the setuid bit set. Not just files with only the setuid bit set.

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12 puneeta April 24, 2012 at 10:41 am

thanks, great !

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