The Interface to the Operating System

 bin_dir()
Returns the directory of the currently executing binary image, SPECTRA or user code which is linked with SPECTRA (sec. 14.6.1).

 chmod
Change file protection (sec. 15.3.8).

 cd
Change default directory (sec. 15.3.5).

 cp
Copy external files (sec. 15.3.15).

 edit
Invokes the EDT/$vi$ editor for a file (sec. 15.3.24). The default editor can be selected by the environment variable EDITOR.

 ls
Show directory (sec. 15.3.44).

 meminfo()
Get information about the memory allocation of the host (sec. 14.6.7).

 mkdir
Create directory (sec. 15.3.46).

 mv
Rename external files (sec. 15.3.47).

 pid()
Returns the process id (sec. 14.6.9).

 rm
Delete external files (sec. 15.3.63).

 shell()
Returns the output of a shell command (sec. ).

 shell command
A sub-process is spawned (sec. 15.3.70).

 wait
Wait some time (sec. 15.3.82).