o.txt
上传用户:harvey99
上传日期:2020-01-11
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文件大小:3k
- 返回>>C语言函数大全
- 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 <string.h>
- #include <stdio.h>
- #include <fcntl.h>
- #include <io.h>
- 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 <stdio.h>
- #include <dos.h>
- int main(void)
- {
- int value = 64;
- int port = 0;
- outportb(port, value);
- printf("Value %d sent to port number %dn", 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 <stdio.h>
- #include <dos.h>
- int main(void)
- {
- int value = 64;
- int port = 0;
- outportb(port, value);
- printf("Value %d sent to port number %dn", 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 <graphics.h>
- #include <stdlib.h>
- #include <stdio.h>
- #include <conio.h>
- 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: %sn", 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 <graphics.h>
- #include <stdlib.h>
- #include <stdio.h>
- #include <conio.h>
- 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: %sn", grapherrormsg(errorcode));
- printf("Press any key to halt:");
- getch();
- exit(1); /* terminate with an error code */
- }
- midx = getmaxx() / 2;
- midy = getmaxy() / 2;
- /* output text at the center of the screen*/
- /* Note: the C.P. doesn't get changed.*/
- outtextxy(midx, midy, "This is a test.");
- /* clean up */
- getch();
- closegraph();
- return 0;
- }
-