Linux – Is it possible to get write/read permissions back after removing all read/write/execute permissions with chmod

chmodlinuxpermissionsunix

I accidentally removed all the permissions from a file. Now I don't have permission to chmod it. Is there any way of chmod(ing) the file back?

Thank you

Best Answer

I suspect there's more going on than your question states, because that shouldn't happen:

[madhatta@risby tmp]$ touch foo
[madhatta@risby tmp]$ chmod 000 foo
[madhatta@risby tmp]$ ls -la foo
----------. 1 madhatta madhatta 0 Dec 28 22:25 foo
[madhatta@risby tmp]$ chmod 644 foo
[madhatta@risby tmp]$ ls -la foo
-rw-r--r--. 1 madhatta madhatta 0 Dec 28 22:25 foo

As you can see, having no access to the file is no bar to changing the mode back. Could you tell us more about what you did, what you see, and what's going wrong?

Related Solutions

Linux – Copying a large directory tree locally? cp or rsync

I would use rsync as it means that if it is interrupted for any reason, then you can restart it easily with very little cost. And being rsync, it can even restart part way through a large file. As others mention, it can exclude files easily. The simplest way to preserve most things is to use the -a flag – ‘archive.’ So:

rsync -a source dest

Although UID/GID and symlinks are preserved by -a (see -lpgo), your question implies you might want a full copy of the filesystem information; and -a doesn't include hard-links, extended attributes, or ACLs (on Linux) or the above nor resource forks (on OS X.) Thus, for a robust copy of a filesystem, you'll need to include those flags:

rsync -aHAX source dest # Linux
rsync -aHE source dest  # OS X

The default cp will start again, though the -u flag will "copy only when the SOURCE file is newer than the destination file or when the destination file is missing". And the -a (archive) flag will be recursive, not recopy files if you have to restart and preserve permissions. So:

cp -au source dest

Linux – How to Set Up Permissions for the WWW Folder

After more research it seems like another (possibly better way) to answer this would be to setup the www folder like so.

sudo usermod -a -G developer user1 (add each user to developer group)
sudo chgrp -R developer /var/www/site.com/ so that developers can work in there
sudo chmod -R 2774 /var/www/site.com/ so that only developers can create/edit files (other/world can read)
sudo chgrp -R www-data /var/www/site.com/uploads so that www-data (apache/nginx) can create uploads.

Since git runs as whatever user is calling it, then as long as the user is in the "developer" group they should be able to create folders, edit PHP files, and manage the git repository.

Note: In step (3): '2' in 2774 means to 'set Group ID' for the directory. This causes new files and sub directories created within it to inherit the group ID of the parent directory (instead of the primary group of the user) Reference: http://en.wikipedia.org/wiki/Setuid#setuid_and_setgid_on_directories

Best Answer

Related Solutions

Linux – Copying a large directory tree locally? cp or rsync

Linux – How to Set Up Permissions for the WWW Folder

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