Linux file permissions

chmod 666 (rw-rw-rw-)

Owner: read, write · Group: read, write · Others: read, write

666numeric

rw-rw-rw-symbolic

6 · 6 · 6owner · group · others

Commands

chmod 666 filename chmod u=rw,g=rw,o=rw filename chmod -R 666 folder/ # apply to a folder and everything in it

Security warning: 666 lets any user on the system modify these files. On web servers use 755 for folders and 644 for files and fix ownership with chown instead.

Change any permission with the chmod calculator.

What chmod 666 means

Who	Digit	Letters	Can
Owner (user)	6	`rw-`	read, write
Group	6	`rw-`	read, write
Others	6	`rw-`	read, write

Each digit is the sum of read (4), write (2) and execute (1).

When to use 666

Files anyone may edit — usually a security risk.

Related permissions

chmod 750see what 750 means chmod 744see what 744 means chmod 711see what 711 means chmod 700see what 700 means chmod 664see what 664 means chmod 660see what 660 means chmod 655see what 655 means chmod 644see what 644 means

Questions

What does chmod 666 mean?

chmod 666 sets the permissions to rw-rw-rw-: the owner can read, write, the group can read, write and others can read, write.

When should I use 666?

Files anyone may edit — usually a security risk.

What is 666 in symbolic form?

666 is rw-rw-rw- (shown by ls -l as -rw-rw-rw- for a file or drw-rw-rw- for a folder). The symbolic chmod command is chmod u=rw,g=rw,o=rw file.