raise —
send a signal to the current thread
Standard C Library (libc, -lc)
The raise() function sends the signal
  sig to the current thread.
Upon successful completion, a value of 0 is returned. Otherwise, a value of -1
  is returned and the global variable errno is set to
  indicate the error.
The raise() function may fail and set
  errno for any of the errors specified for the library
  functions _lwp_self(2) and
  _lwp_kill(2).
The raise() function conforms to ANSI
  X3.159-1989 (“ANSI C89”) and
  Version 2 of the Single UNIX Specification
  (“SUSv2”).