Calculate and convert Unix file permissions between octal and symbolic notation
| Read (4) | Write (2) | Execute (1) | Value | |
|---|---|---|---|---|
| Owner (u) | 6 | |||
| Group (g) | 4 | |||
| Others (o) | 4 |
644
-rw-r--r--
chmod 644 filename
Read (4): View file contents or list directory contents
Write (2): Modify file or create/delete files in directory
Execute (1): Run file as program or access files in directory
Special Bits: SUID allows running as owner, SGID as group, Sticky bit prevents deletion by non-owners in shared directories.