chmod 700 rwx------

chmod 700 (rwx------): the owner can read, write and execute; group and others can do nothing. Typical use: ~/.ssh and private directories.

Octal: 700 (also written 0700)
Symbolic: rwx------
ls -l shows: -rwx------ for a file, drwx------ for a directory
chmod letters: u=rwx,g=,o=

Who can do what

Class	Digit	Bits	On a file	On a directory
Owner (u)	7	`rwx`	Read the contents, change or empty the contents and run it as a program	List the names inside, create, delete and rename entries and enter it and open files by name
Group (g)	0	`---`	Nothing	Nothing
Others (o)	0	`---`	Nothing	Nothing

Each digit adds read (4), write (2) and execute (1). Deleting or renaming a file depends on write and execute on the directory that holds it, not on the file's own mode. Root bypasses read and write checks.

Typical uses

The owner has full access, everyone else none. It is the mode OpenSSH expects for ~/.ssh, the default for new home directories on Fedora and RHEL, and the right choice for private scripts and backup folders.

Security notes

Nobody but the owner (and root) has any access, the safest setting for secrets.

Commands

Numeric
chmod 700 file
Symbolic
chmod u=rwx,g=,o= file
Check the result
stat -c '%a %A %n' file
Directories only, recursively
find /path -type d -exec chmod 700 {} +

Avoid chmod -R 700 on a tree that holds files as well as folders: it makes every file executable. Use the find command above for directories and a file mode such as 600 for the files.

The umask that gives 700

umask 077: new directories are created as 700 (and files as 600)

Programs create files with 666 and directories with 777, and the umask removes bits from those. A umask never adds execute to a new file, and it cannot set setuid, setgid or the sticky bit.

Its file counterpart is chmod 600 (rw-------).

Other common modes

Work out any other mode in the chmod calculator