### Example (_inp -- Read Byte from Input Port)

This example uses _inp to read a byte from a specified input port and return the data read.

    #include <builtin.h>

    #define LOWER 0
    #define UPPER 65535

    int Add1(int j);

    int    g;
    enum   fruit {apples=10, bananas, cantaloupes};
    int    arr[] = {cantaloupes, bananas, apples};
    struct
    {
       int  i;
       char ch;
    } st;

    int main(void)
    {
       int i;
       volatile const int c = 0;

       i = _inp(0);
       g = _inp(LOWER + 1);    /* put the data read in a global variable  */
       i = _inp(apples);          /* passing enumerated type as the       */
                                  /* port number                          */
                                  /* ===================================  */
                                  /* Types of port number passed :        */
                                  /* -----------------------------------  */
       i = _inp(c);               /* - constant                           */
       i = _inp(arr[c]);          /* - element of array                   */
       st.i = Add1(c);            /*                                      */
       i = _inp(st.i);            /* - element of structure               */
       i = _inp(Add1(LOWER));     /* - return value from a function call  */
       i = _inp(UPPER);           /* - #define constant                   */
       i = _inp(256);             /* - the exact port number              */
                                  /* -----------------------------------  */
       return 0;
    }

    int Add1(int j)
    }
       j += 1;
       return j;
    }