v7 man page for indir

INDIR(2)							System Calls Manual							  INDIR(2)

NAME
       indir - indirect system call

ASSEMBLER
       (indir = 0.)
       sys indir; call

       The system call at the location call is executed.  Execution resumes after the indir call.

       The  main purpose of indir is to allow a program to store arguments in system calls and execute them out of line in the data segment.  This
       preserves the purity of the text segment.

       If indir is executed indirectly, it is a no-op.	If the instruction at the indirect location is not a system call, indir returns error code
       EINVAL; see intro(2).

																	  INDIR(2)