Provides a way to transfer control from a nested series of
    function invocations back to a predefined point without returning
    normally. It does not use a series of return statements. The
    setjmp function saves the context of the calling function in an
    environment buffer.

    Format

      #include  <setjmp.h>

      int setjmp  (jmp_buf env);

  Additional Information (explode) :

• Argument
• Description
• Restrictions
• Return Values