fjordtools / DevOps / Chmod Calculator
Chmod Calculator: Unix Permissions
Calculate Unix file permissions: tick read, write and execute, or type 755, rwxr-xr-x or u=rwx,go=rx. Includes setuid, setgid and sticky. Runs in your browser.
| Read | Write | Execute | Special | |
|---|---|---|---|---|
| User | ||||
| Group | ||||
| Other |
About Chmod Calculatorhow it works and good to know
Reading a mode
A Unix mode is three groups of read, write and execute for the user who owns the file, the group, and everyone else. 755 means rwxr-xr-x: the owner can do everything, others can read and run. Each digit is read 4 + write 2 + execute 1.
Special bits
setuid (4000) and setgid (2000) run a program as its owner or group. sticky (1000) on a directory, as on /tmp, lets only a file's owner delete it. In the ls form they show as s and t, or capital S and T when the execute bit is off.
Symbolic mode
Type clauses such as u=rwx,go=rx or a+x; they are applied to the mode shown in the grid, like chmod does. Every clause needs who letters (u, g, o, a), because a bare +x depends on your umask. The calculator follows the rules for regular files; for directories GNU chmod keeps an existing setuid or setgid bit unless you name s.
Privacy
Everything is computed in your browser. Nothing is uploaded or stored.
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