umask(1)

NAME
umask - set or get the file-creation mask

  Synopsis
umask [OPTIONS] [MASK]

  Description
With no argument, the current file-creation mask is printed, if an argument is specified, it is the new file creation mask. The mask may be specified as an octal number, in which case it is interpreted as the rights that should be masked away, i.e. it is the inverse of the file permissions any new files will have.

If a symbolic mask is specified, the actual file permission bits, and not the inverse, should be specified. A symbolic mask is a comma separated list of rights. Each right consists of three parts:

•   The first part specifies to whom this set of right applies, and can be one of u, g, o or a, where u specifies the user who owns the file, g specifies the group owner of the file, o specific other users rights and a specifies all three should be changed.

•   The second part of a right specifies the mode, and can be one of =, + or -, where = specifies that the rights should be set to the new value, + specifies that the specified right should be added to those previously specified and - specifies that the specified rights should be removed from those previously specified.

•   The third part of a right specifies what rights should be changed and can be any combination of r, w and x, representing read, write and execute rights.

If the first and second parts are skipped, they are assumed to be a and =, respectively. As an example, r,u+w means all users should have read access and the file owner should also have write access.

•   -h or --help print this message

•   -S or --symbolic prints the file-creation mask in symbolic form instead of octal form. Use man chmod for more information.

•   -p or --as-command prints any output in a form that may be reused as input

The umask implementation in fish should behave identically to the one in bash.

  Example
umask 177 or umask u=rw sets the file creation mask to read and write for the owner and no permissions at all for any other users.