outb(2) System Calls Manual outb(2) outb, outw, outl, outsb, outsw, outsl, inb, inw, inl, insb, insw, insl, outb_p, outw_p, outl_p, inb_p, inw_p, inl_p - / C (libc, -lc) #include unsigned char inb(unsigned short port); unsigned char inb_p(unsigned short port); unsigned short inw(unsigned short port); unsigned short inw_p(unsigned short port); unsigned int inl(unsigned short port); unsigned int inl_p(unsigned short port); void outb(unsigned char value, unsigned short port); void outb_p(unsigned char value, unsigned short port); void outw(unsigned short value, unsigned short port); void outw_p(unsigned short value, unsigned short port); void outl(unsigned int value, unsigned short port); void outl_p(unsigned int value, unsigned short port); void insb(unsigned long count; unsigned short port, void addr[count], unsigned long count); void insw(unsigned long count; unsigned short port, void addr[count], unsigned long count); void insl(unsigned long count; unsigned short port, void addr[count], unsigned long count); void outsb(unsigned long count; unsigned short port, const void addr[count], unsigned long count); void outsw(unsigned long count; unsigned short port, const void addr[count], unsigned long count); void outsl(unsigned long count; unsigned short port, const void addr[count], unsigned long count); /. out* , in* ; b , w ; _p -. , , . -O, -O2 . , . , - , , ioperm(2) iopl(2). , . outb() . value , port -- , DOS. . ioperm(2), iopl(2) () Azamat Hackimov , Konstantin Shvaykovskiy , Yuri Kozlov ; GNU (GNU General Public License - GPL, 3 ) , - . - , , () () () . Linux man-pages 6.18 8 2026 . outb(2)