chmod 666 — what rw-rw-rw- means
666
rw-rw-rw-
Everyone can read and write, but nobody can execute.
⚠️ Risky permission. This grants write access beyond the owner — only use it when you truly need it, and prefer tighter, group-based permissions where you can.
Permission breakdown
When to use 666
Rarely correct. Any user can overwrite the file's contents. Occasionally seen on device or scratch files, but for shared writable data prefer group-based 664 over world-writable 666.
Set it with chmod
Apply this permission to a file:
chmod 666 filenameOr apply it recursively to a directory and everything inside it:
chmod -R 666 directory/Other common permissions
Or build any permission with the interactive chmod calculator.