chmod 640 — rw-r-----
What chmod 640 allows, when to use it, and the calculator pre-filled with it — toggle any box to compare.
640
rw-r-----Owner6
rw-Group4
r--Others0
---Special bits
chmod 640 filenamechmod -R 640 /path/to/dirWhat this means
Owner can read, write. Group can read. Others has no permissions.
What chmod 640 allows
| Who | Read | Write | Execute |
|---|---|---|---|
| Owner | ✓ | ✓ | — |
| Group | ✓ | — | — |
| Others | — | — | — |
Config files a service reads through its group but other users must not see, like database or web server configs with passwords.
Commands
chmod 640 fileset it on one file or directorychmod u=rw,g=r,o= filethe same thing in symbolic formchmod -R 640 dir/recursively — careful: it applies to files and directories alikels -l filecheck the result: -rw-r----- (a directory shows drw-r-----)On a directory, read lets you list it, write lets you create and delete entries, and execute lets you enter it and open what's inside. That's why directories usually get 755 or 750 while files get 644 or 640.
Frequently asked
What does chmod 640 mean?
Owner: read, write. Group: read. Others: no access. In ls -l it shows as rw-r-----.
What is the symbolic form of chmod 640?
chmod u=rw,g=r,o= file — it sets exactly the same permissions as chmod 640.
Common chmod permissions explained
chmod 755rwxr-xr-xchmod 644rw-r--r--chmod 777rwxrwxrwxchmod 600rw-------chmod 700rwx------chmod 775rwxrwxr-xchmod 664rw-rw-r--chmod 400r--------chmod 444r--r--r--chmod 750rwxr-x---chmod 640rw-r-----chmod 660rw-rw----chmod 770rwxrwx---chmod 666rw-rw-rw-chmod 711rwx--x--xchmod 500r-x------chmod 550r-xr-x---chmod 555r-xr-xr-xchmod 440r--r-----chmod 740rwxr-----chmod 760rwxrw----chmod 1777rwxrwxrwtchmod 2755rwxr-sr-xchmod 2775rwxrwsr-xchmod 4755rwsr-xr-x
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