DragonFly On-Line Manual Pages

SYSCALL(2)               DragonFly System Calls Manual              SYSCALL(2)

NAME
     syscall, __syscall -- indirect system call

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <sys/syscall.h>
     #include <unistd.h>

     int
     syscall(int number, ...);

     off_t
     __syscall(quad_t number, ...);

DESCRIPTION
     Syscall() performs the system call whose assembly language interface has
     the specified number with the specified arguments.  Symbolic constants
     for system calls can be found in the header file <sys/syscall.h>.  The
     __syscall() form should be used when one or more of the parameters is a
     64-bit argument to ensure that argument alignment is correct.  This sys-
     tem call is useful for testing new system calls that do not have entries
     in the C library.

RETURN VALUES
     The return values are defined by the system call being invoked.  In gen-
     eral, a 0 return value indicates success.  A -1 return value indicates an
     error, and an error code is stored in errno.

HISTORY
     The syscall() function call appeared in 4.0BSD.

BUGS
     There is no way to simulate system calls that have multiple return values
     such as pipe(2).

DragonFly 3.5                    June 16, 1993                   DragonFly 3.5