.TH SYSCALL 2 "12 February 1983" .UC 4 .SH NAME syscall \- indirect system call .SH SYNOPSIS .nf .BR "syscall(number, arg, ...)" \ \ (VAX-11) .fi .SH DESCRIPTION .I Syscall performs the system call whose assembly language interface has the specified .I number, register arguments .I r0 and .I r1 and further arguments .IR arg . .PP The r0 value of the system call is returned. .SH DIAGNOSTICS When the C-bit is set, .I syscall returns \-1 and sets the external variable .I errno (see .IR intro (2)). .SH BUGS There is no way to simulate system calls such as .IR pipe (2), which return values in register r1.