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Am 25.03.2010 09:50, schrieb Alan McKinnon: |
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> On Thursday 25 March 2010 10:26:25 Hinko Kocevar wrote: |
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>> Hi, |
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>> |
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>> Where is defined what permissions will the newly created folder/file |
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>> have by default? |
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> |
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> This is done by the umask of the user creating the folder. |
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> |
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> |
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>> |
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>> Eg. When creating a folder I would like it to have permissions right |
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>> after it is created, to void use of chmod/chown afterwards: |
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>> |
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>> drwxrwxr-x 2 hinko users 4096 Mar 25 09:23 folder1 |
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>> |
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>> while now I get only: |
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>> drwxr-xr-x 2 hinko users 4096 Mar 25 09:23 folder1 |
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>> |
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>> That is group should have 'w' set. |
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> |
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> |
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> This is a common misunderstanding about permissions and the Unix philosophy |
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> about them, which is: |
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> |
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> It's up to the user, not the system, to say what permissions he wants on new |
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> filesystem objects. |
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> |
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> Modifing the user's umask is not advised, as this is global. *Every* new file |
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> or dir then ends up with g+w and you probably don't want that. |
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> |
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> You need to use Posix ACLs for this, and your file system and kernel must |
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> support them; you configure it per directory. It's all in man pages and on |
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> google - better start reading. |
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> |
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> Be warned though: you *will* forget you set this, and *will* wonder in future |
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> why g+w is set in various places. "ls" gives precious little clue that an ACL |
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> is in place. |
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> |
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> I find that in real life, a "find -exec chmod" in a cron is a better solution |
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> |
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|
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To avoid ACLs and still have group rw rights on some folders for |
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specific groups, you can make use of the 'user private group' scheme and |
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the setgid bit: [1]. |
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|
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Gentoo uses this scheme per default, although I think the umask setting |
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is different (has to be 002 or 007). |
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|
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What Alan forgot to tell is where to set the umask: /etc/profile. Don't |
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use too strict settings because these are also applied to system |
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accounts. This can easily break your system. |
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|
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[1] |
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http://www.redhat.com/docs/manuals/linux/RHL-7.3-Manual/ref-guide/s1-users-groups-private-groups.html |
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|
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Hope this helps, |
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Florian Philipp |
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