函数名: open 功 能: 打开一个文件用于读或写 用 法: int open(char *pathname, int access[, int permiss]). 程序例: #include #include #include #include int main(void) { int handle. char msg[] = "Hello world". if ((handle = open("TEST.$$$", O_CREAT | O_TEXT)) == -1) { perror("Error:"). return 1. } write(handle, msg, strlen(msg)). close(handle). return 0. }
函数名: outport 功 能: 输出整数到硬件端口中 用 法: void outport(int port, int value). 程序例: #include #include int main(void) { int value = 64. int port = 0. outportb(port, value). printf("Value %d sent to port number %d\n", value, port). return 0. }
函数名: outportb 功 能: 输出字节到硬件端口中 用 法: void outportb(int port, char byte). 程序例: #include #include int main(void) { int value = 64. int port = 0. outportb(port, value). printf("Value %d sent to port number %d\n", value, port). return 0. }
函数名: outtext 功 能: 在视区显示一个字符串 用 法: void far outtext(char far *textstring). 程序例: #include #include #include #include int main(void) { /* request auto detection */ int gdriver = DETECT, gmode, errorcode. int midx, midy. /* initialize graphics and local variables */ initgraph(&.gdriver, &.gmode, ""). /* read result of initialization */ errorcode = graphresult(). if (errorcode != grOk) /* an error occurred */ { printf("Graphics error: %s\n", grapherrormsg(errorcode)). printf("Press any key to halt:"). getch(). exit(1). /* terminate with an error code */ } midx = getmaxx() / 2. midy = getmaxy() / 2. /* move the C.P. to the center of the screen */ moveto(midx, midy). /* output text starting at the C.P. */ outtext("This "). outtext("is "). outtext("a "). outtext("test."). /* clean up */ getch(). closegraph(). return 0. }
函数名: outtextxy 功 能: 在指定位置显示一字符串 用 法: void far outtextxy(int x, int y, char *textstring). 程序例: #include #include #include #include int main(void) { /* request auto detection */ int gdriver = DETECT, gmode, errorcode. int midx, midy. /* initialize graphics and local variables */ initgraph( &.gdriver, &.gmode, ""). /* read result of initialization */ errorcode = graphresult(). if (errorcode != grOk) /* an error occurred */