18

I've been trying to clean up permissions on a few boxes and have been scouring the chmod man as well as all the internet documentation that I an handle without any luck -- so here we go.

Basically, I've got a directory with many sub directories and files -- and I'd like to set the following permissions:

For directories: 770 (u+rwx, g+rwx, o-rwx)

For files: 660 (U+rw, g+rw, a-x, o-rw)

I'd like to try and do this with a single recursive chmod if possible -- as to avoid recursing through each directory and setting file-by-file permissions.

I imagine there's got to be a way to do this without writing a shell script of my own -- but I haven't been able to find anything.

I appreciate your help!

5 Answers 5

12

I do find a script useful since it's often useful to change both file and directory permissions in one swoop, and they are often linked. 770 and 660 for shared directories on a file server, 755/644 for web server directories, etc. I keep a script w/ the most commonly used mode for that type of server in root's bin/ and just do the find manually when the common mode doesn't apply.

#!/bin/sh
# syntax: setperm.s destdir
#
if [ -z $1 ] ; then echo "Requires single argument: <directoryname>" ; exit 1 ;                                       fi

destdir=$1

dirmode=0770
filemode=0660

YN=no

printf "\nThis will RECURSIVELY change the permissions for this entire branch:\n                                      "
printf "\t$destdir\n"
printf "\tDirectories chmod = $dirmode\tFiles chmod = $filemode\n"
printf "Are you sure want to do this [$YN]? "

read YN

case $YN in
        [yY]|[yY][eE][sS])
        # change permissions on files and directories.
        find $destdir -type f -print0 | xargs -0 chmod $filemode $i
        find $destdir -type d -print0 | xargs -0 chmod $dirmode $ii ;;

        *) echo "\nBetter safe than sorry I always say.\n" ;;
esac
2
  • Wow! This is exactly what I was looking for. Thank you very much!
    – Skone
    Jan 21, 2010 at 0:33
  • Hey iPaulo -- can you by chance explain the "$ii" on the line "find $destdir -type d -print0 | xargs -0 chmod $dirmode $ii ;;". I'm not sure I understand why its not just "find $destdir -type d -print0 | xargs -0 chmod $dirmode $i ;;" Thanks!
    – Skone
    Jan 21, 2010 at 19:35
27

No need for scripts.

// Directories:

find . -type d -exec chmod 770 '{}' \;

// Files:

find . -type f -exec chmod 660 '{}' \;
0
23

In your case it might not have to be as complicated as others has made it out to be (though find is indeed a good tool for this sort of thing in general). The difference between the modes are the execute bit. If it is the case that no files already has the execute bit set, then you can do it in a single invocation of chmod, just as you asked.

chmod -R u=rwX,g=rwX,o= FILE...

The key here is the capital X, which the man page explains as

execute/search only if the file is a directory or already has execute permission for some user.

Thus, if your files do not already have the execute bit set, it will only be set for directories.

1
  • This is great, but much longer than just writing 777. Is there a shorthand for the -X ?
    – Elliott B
    Apr 23, 2018 at 22:49
7

I found that for my use case at least, using rsync to copy the directory onto itself was much faster than using chmod directly with a list of files from find.

rsync -rpt --chmod=D770,F660 . .

If you want to add a chown to the same operation, rsync lets you do that too with the --chown=user:group option.

3
  • Whoah, this actually a lot faster than chmod -R.
    – esamatti
    Dec 3, 2018 at 17:46
  • So much faster than chmod. Are there any downsides to using rsync this way? I've been doing it a lot and everything seems fine.
    – slothbear
    May 12, 2020 at 1:36
  • It's also worth noting that if you want to use the --chown option you'll also need to add the -o and -g flags. That seems a little counter-intuitive but --chown is shorthand for some other more verbose options, and those options don't have any effect if -o and -g are missing. Sep 10, 2022 at 1:07
1

Clean and simple:

chmod 660 $(find . -type f)
chmod 770 $(find . -type d)
2
  • Very elegant approach.
    – user5336
    Sep 13, 2010 at 17:12
  • 4
    perhaps, but note that this only works if the files have no spaces in them. A more "safe" approach is find ... -exec chmod ... {} \;
    – isaaclw
    Jul 18, 2012 at 22:30

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