SYSCALL(2) System Calls Manual SYSCALL(2)
syscall - indirect system call
int syscall(number[ , arg, ... ] )
syscall() performs the system call whose assembly language interface
has the specified number, and arguments arg .... Symbolic constants
for system calls can be found in the header file <<sys/syscall.h>>.
syscall() returns the return value of the system call specified by num-
There is no way to use syscall() to call functions such as pipe(2V),
which return values that do not fit into one hardware register.
Since many system calls are implemented as library wrappers around
traps to the kernel, these calls may not behave as documented when
called from syscall(), which bypasses these wrappers. For these rea-
sons, using syscall() is not recommended.
21 January 1990 SYSCALL(2)