finding filesystems /dirs/files belonging to a user

[Chern Jian Leaw]

HI,

I'm trying to find directories and files within a filesystem belonging to a particular user and change their uids.

The problem is there're many other filesystems containing dirs/files which may belong to a particular user.

I did the following below:
#cat findUser.sh
for i in `cat $1`
do
find $i -user joe_black -exec chown kevin_lee $i {}\;
done

$1 is the lists of filesystems to be searched for that particular user.

A sample of $1 would be:
#cat file1.txt
/fs1/test_tools/
/fs2/auto_cad/lib
/fs3/regression_test/
.... (the list continues ...)

I've tried breaking the list and placing smaller numbers of filesystem lists into a other files. But the search time is simply to slow given the enormity of the filesystems structure.

Could some one help me out on providing more efficient ways or some scripts to improve the efficiency of this task?

Thanks.

[Michael Tully · Accepted solution]

Change your find command line to something like this:

find $i -user joe_black | xargs chown kevin_lee

xargs is far more efficient at doing these type of tasks.

[Ralph Grothe]

I find the loop not utterly performant because you invoke a new find process for every filesystem placed in $i.
I would rather do it like this (provided the file with the filesystems isn't too big ;-)

find $(cat /file/with/filesystems) -user joe_black -print | xargs chhown ...

[Chern Jian Leaw]

Michael, Ralph,

There're lots and lots of sub-directories and files within each of the searched filesystems.

Ralph,
Do you mean to say I should just eliminate the for-loop and call:

find $(cat /filesystems/) -user joe_black |xargs chown kevin_lee ??

I'd need to refer to the list of all available filesystems on my system and find this user joe_black and do a chown.

Could you please help me out?

Thanks.

[Trond Haugen]

As Michael pointed out xargs is faster. But also if you use a list of filesystems you would want to use the '-xdev' options to find to avoid searching filesystems more than once.

Regards,
Trond

[Ralph Grothe]

Hi Chern,

yes that's what I meant, forget about the loop.
But if you are interested in all locally mounted filesystems of your system, I think you do not need to hold an extra list in a file.
I would rather parse the output of mount or better bdf

e.g.

find $(bdf -l|awk '{print $NF}') -xdev -user joe_black | xargs chown new_owner

Beware to use the -xdev flag of find (read the find manpage) to prevent subdecending into other submounts.

[Ralph Grothe]

Oops,

a little flaw, I forgot about the heading, which we have to get rid of.
Just insert a wee sed like this (there will probably be no mount on 'on' ;-)

find $(bdf -l|sed '1d'|awk '{print $NF}') ...

[Ralph Grothe]

Nonsense, we don't need the extra sed, because awk can do this on its own:

find $(bdf -l|awk 'NR>1 {print $NF}')

[Ralph Grothe]

Sorry,

I again forgot to think before I posted (thus making my last three posts a complete embarrasement of the senses)
Forget the bdf stuff altogether because this is the same as "find / ..."
%-P

[Chern Jian Leaw]

Ralph,

What does the %-P option do? I'm not able to find this option in the manpages for find.

Do I just say:
find ... %-P |xargs chown kevin_lee ??

Thanks.

[Ralph Grothe]

Oh sorry for misleading you,
this is no option at all but a silly kind of smily.
Just turn your head to the left and look at it.
The characters should resemble a confused mind (i.e. me) that sticks out his tongue.

:-)