ultrix man page for syscall

syscall(2)							System Calls Manual							syscall(2)

Name
       syscall - indirect system call

Syntax
       syscall(number, args, ...)

Description
       The system call performs the system call whose assembly language interface has the specified number, and further arguments args.  There may
       be no arguments.

       The return value of the system call is returned.

Diagnostics
       If an error occurs, returns -1 and sets the external variable errno.

See Also
       errno(2)

								       RISC								syscall(2)