Provided by: manpages-dev_3.35-0.1ubuntu1_all _syscall -
invoking a system call without library support (OBSOLETE) A
_syscall macro desired system call The important thing to know
about a system call is its prototype. You need to know how many
arguments, their types, and the function return type. There are
seven macros that make the actual call into the system easier.
They have the form: X is 0-6, which are the number of arguments
taken by the system type is the return type of the system call
name is the name of the system call typeN is the Nth argument's
type argN is the name of the Nth argument These macros create a
function called name with the arguments you specify. Once you
include the _syscall() in your source file, you call the system
call by name. The use of these macros is Linux-specific, and
deprecated. Starting around kernel 2.6.18, the _syscall macros
were removed from header files supplied to user space. Use
syscall(2) instead. (Some architectures, notably ia64, never
provided the _syscall macros