Miscellaneous

?X = ?Y

Defined as if by the clause Z=Z.; i.e. X and Y are unified.

length(?List,?Length)

If List is instantiated to a list of determinate length, then Length will be unified with this length.

If List is of indeterminate length and Length is instantiated to an integer, then List will be unified with a list of length Length. The list elements are unique variables.

If Length is unbound then Length will be unified with all possible lengths of List.

copy_term(?Term,?CopyOfTerm)

CopyOfTerm is a renaming of Term, such that brand new variables have been substituted for all variables in Term.

argv(?Args)

Args is unified with a list of atoms of the program arguments supplied after the -a option on the command line.

cd

Change the current working directory to the home directory.

shell(+Command,-Status)

Pass Command to a new UNIX shell named in the Unix environment variable $SHELL for execution. Unify Status with the returned status of Command.

system(+Command,-Status)

Pass Command to a new UNIX sh process for execution. Unify Status with the returned status of Command.

mktemp(+Template,-FileName)

Interface to the C-function mktemp(3). A unique file name is created and unified with FileName. Template should contain a file name with six trailing Xs. The file name is that template with the six Xs replaced with a letter and the process id.

access(+Path,+Mode)

Tests if Mode is the accessability of Path as in the C-function access(2).

getwd(?Path)

Unify Path with the atom representation of the current working directory.

getenv(+Name,?Value)

Unify Value with the atom representation of the value of the environment variable given by Name.

gensym(-Id)

Unify Id with a fresh integer.

domain(x?X,+List)

A built-in oriented version of member/2.