1 //文件路径
 2     char path[150] = "1.txt";
 3
 4
 5     //FILE *pf = fopen(path, "a+");//尾部添加,文件指针在尾部
 6     //FILE *pf = fopen(path, "w+");//文件指针在头部，清空内容
 7     FILE *pf = fopen(path, "r+");//文件指针在头部，不清空内容
 8     fseek(pf, 0, SEEK_END);
 9     fputs("0000000", pf);
10     fflush(pf);//刷新文件
11
12
13     //插入
14     int length = 10;
15     for (int i = 0; i < 10;i++)
16     {
17         fseek(pf, -7-i-1, SEEK_END);
18         int ch = fgetc(pf);
19 //#define SEEK_CUR    1 当前
20 //#define SEEK_END    2 结束
21 //#define SEEK_SET    0  开头
22
23         fseek(pf, -i-1, SEEK_END);
24         fputc(ch,pf);
25         fflush(pf);//刷新文件
26     }
27     fseek(pf, -17, SEEK_END);//a+ 文件指针移动无效
28                              //r+，文件覆盖
29     fputs("abcdefg", pf);
30     fflush(pf);//刷新文件
31
32     fclose(pf);

 1     char path[150] = "1.txt";
 2     FILE *pf = fopen(path, "rb+");//文件指针在头部，不清空内容
 3
 4     fseek(pf, -20, SEEK_END);//a+ 文件指针移动无效
 5     fputc('8', pf);
 6     fputs("123545", pf);
 7
 8     rewind(pf);
 9
10     char ch;
11     while ((ch=fgetc(pf))!=EOF)
12     {
13         putchar(ch);
14     }
15
16     fclose(pf);

 1 //设定中文
 2     setlocale(LC_ALL, "zh-CN");
 3     wchar_t path[150] = L"Z:\\I\\百度内部员工联系方式.txt";
 4     //文件指针在头部，不清空内容
 5     FILE *pf = _wfopen(path, L"r");
 6
 7     if (pf==NULL)
 8     {
 9         printf("error");
10     }
11     wchar_t wstr[1128] = { 0 };
12     wchar_t *p = fgetws(wstr, 1128, pf);
13     wprintf(L"-%s-\n", wstr);
14     p = fgetws(wstr, 1128, pf);
15     while (p!=NULL)
16     {
17         //输出
18         wprintf(L"-%s-\n", wstr);
19         p = fgetws(wstr, 1128, pf);
20     }
21
22     fclose(pf);

1 //fgetc  fgetwc
2 //fputc fputwc
3 //fgets fgetws
4 //fputs fputws
5 //fprintf  fwprintf
6 //fscanf fwscanf
7
8 //fread ,fwrite

 1     setlocale(LC_ALL, "zh-CN");
 2     FILE *pfr = _wfopen(L"QQ-腾讯通讯录.txt", L"rb");
 3     FILE *pfw = _wfopen(L"QQc.txt", L"wb");
 4     while (!feof(pfr))
 5     {
 6         wchar_t ch = fgetwc(pfr);//获取宽字符
 7         fputwc(ch, pfw);
 8         putwchar(ch);//显示宽字符
 9
10     }
11     fclose(pfr);
12     fclose(pfw);

 1        setlocale(LC_ALL, "zh-CN");
 2     FILE *pfr = _wfopen(L"QQ-腾讯通讯录.txt", L"rb");
 3     FILE *pfw = _wfopen(L"QQ.txt", L"wb");
 4     while (!feof(pfr))
 5     {
 6         wchar_t wstr[256] = { 0 };
 7         fgetws(wstr, 256, pfr);
 8         wprintf(L"%ls",wstr);
 9         fputws(wstr, pfw);//宽字符写入
10
11     }
12     fclose(pfr);
13     fclose(pfw);

1         setlocale(LC_ALL, "zh-CN");
2     wchar_t wstr[100] = { 0 };
3     fwscanf(stdin, L"%s", wstr);
4     fwprintf(stdout, L"%s%d%s", L"你好", 100,wstr);