How to remove executable bit recursively from files (not directories)

chmod

When I plug-in an USB stick (FAT) into my Mac or Ubuntu machine, all files have the executable bits set. After having copied the directory structure to my hard disk how do I remove the executable bits recursively just from the files and keep those on the directories?

Best Answer

With GNU chmod (on Ubuntu) single command variant (starting in the current directory):

chmod -R -x+X .

Explanation:

-R - operate recursively
-x - remove executable flags for all users
+X - set executable flags for all users if it is a directory

In this case the capital X applies only to directories because all executable flags were cleared by -x. Otherwise +X sets executable flag(s) also if the flag was originally set for any of user, group or others.

With BSD chmod (which is present on Mac OS X) you have to do it separately in two commands:

sudo chmod -R -x * && sudo chmod -R +X *

(If you want to include hidden files in the main directory as well, you likely need to change * to . (point), but it is untested.)

Related Solutions

How to recursively chmod all directories except files

To recursively give directories read&execute privileges:

find /path/to/base/dir -type d -exec chmod 755 {} +

To recursively give files read privileges:

find /path/to/base/dir -type f -exec chmod 644 {} +

Or, if there are many objects to process:

chmod 755 $(find /path/to/base/dir -type d)
chmod 644 $(find /path/to/base/dir -type f)

Or, to reduce chmod spawning:

find /path/to/base/dir -type d -print0 | xargs -0 chmod 755 
find /path/to/base/dir -type f -print0 | xargs -0 chmod 644

Linux – Do I correctly understand permission to directories in Linux/Unix

The question says:

If your directory has only "r" (read) permission you are allowed to see the content of the directory (which files are located there) but you cannot do it because you cannot go ("cd") to this directory (because of the absence of "x" permissions).

Yes, you can do it, you can see the list of files that are contained by the directory:

$ mkdir mydir
$ echo text > mydir/myfile
$ chmod a-wx mydir
$ ls -lA
total 4
dr--r--r-- 2 hcs hcs 4096 2010-02-28 22:12 mydir
$ ls -lA mydir
ls: cannot access mydir/myfile: Permission denied
total 0
-????????? ? ? ? ?                ? myfile

But you won't access any other information from the file than its name, as the list shows.

Best Answer

Related Solutions

How to recursively chmod all directories except files

Linux – Do I correctly understand permission to directories in Linux/Unix

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