记录：数据类型-优快云博客

本文探讨了C/C++编程语言中__int64数据类型的使用方法及其格式化输出方式，并通过具体代码示例解释了该类型的实现细节。

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把书本上没有见过的一些类型记录在此，可以回顾。！！~~

在优快云的论坛上提供了一段代码：

其中出现了一个在此之前没有看过的数据类型。记录一下。

View Code

  1 #include <sys\stat.h>
  2 #include <io.h>
  3 #include <fcntl.h>
  4 #include <share.h>
  5 #include <stdlib.h>
  6 #include <stdio.h>
  7 #include <conio.h>
  8 #include <string.h>
  9 #define MAX_CLU_BYTES 65536
 10 FILE *fo;
 11 int fh;
 12 __int64 offs,offs1;
 13 __int64 rvi64;
 14 int rv,wrv;
 15 unsigned char buf[MAX_CLU_BYTES];
 16 char ofn[_MAX_PATH];
 17 char offstr[80];
 18 void strcpybutcomma(char *t,char *s) {
 19     char c;
 20 
 21     while (1) {
 22         c = *s++;
 23         if (','!=c) *t++ = c;
 24         if (0==c) break;
 25     }
 26 }
 27 void main(int argc,char **argv) {
 28     if (argc<3) {
 29         printf("Copy File Tail.\n");
 30         printf("Usage:\n");
 31         printf("    cft filename.ext offset_begin[-offset_end]\n");
 32         printf("Copy filename.ext offset_begin[-offset_end] to offset_begin[-offset_end]-filename.ext\n");
 33         printf("Note: Byte at offset_end is NOT included.\n");
 34         printf("Example:\n");
 35         printf("    cft abc.rar 12345\n");
 36         printf("Copy abc.rar offset 12345-end to 12345-abc.rar\n");
 37         printf("    cft abc.rar 123-12345\n");
 38         printf("Copy abc.rar offset 123-12345 to 123-12345-abc.rar\n");
 39         printf("    cft abc.rar 0xAB-0xCD\n");
 40         printf("Copy abc.rar offset 0xAB-0xCD to 0xAB-0xCD-abc.rar\n");
 41         return;
 42     }
 43     strcpybutcomma(offstr,argv[2]);
 44     rv=sscanf(offstr,"%I64i-%I64i",&offs,&offs1);
 45     if (rv==0) {
 46         printf("offset %s is not number\n",argv[2]);
 47         return;
 48     }
 49     fh=_sopen(argv[1],_O_BINARY|_O_RDONLY|_O_RANDOM,_SH_DENYWR);
 50     if (fh==-1) {
 51         printf("_sopen %s errno=%d\n",argv[1],errno);
 52         return;
 53     }
 54     if (rv==1) {
 55         offs1=_filelengthi64(fh);
 56         if (offs1==-164i) {
 57             printf("%I64=_filelengthi64 errno=%d\n",offs1,errno);
 58             _close(fh);
 59             return;
 60         }
 61     } else {//rv==2
 62         if (offs1<offs) {
 63             printf("%s offset_begin>offset_end error\n",argv[2]);
 64             _close(fh);
 65             return;
 66         }
 67     }
 68     rvi64=_lseeki64(fh,offs,SEEK_SET);
 69     if (rvi64!=offs) {
 70         printf("%I64u=_lseeki64 %I64u errno=%d\n",rvi64,offs,errno);
 71         _close(fh);
 72         return;
 73     }
 74     sprintf(ofn,"%s-",offstr);
 75     strcat(ofn,argv[1]);
 76     fo=fopen(ofn,"wb");
 77     if (fo==NULL) {
 78         _close(fh);
 79         printf("fopen %s error\n",ofn);
 80         return;
 81     }
 82     cprintf("\n%I64u\r",offs);
 83     while (1) {
 84         rv=_read(fh,buf,(unsigned int)__min(offs1-offs,MAX_CLU_BYTES));
 85         if (rv==0) break;//
 86         if (rv<0) {
 87             fclose(fo);
 88             _close(fh);
 89             printf("_read %s offset %I64u error\n",argv[1],offs);
 90             return;
 91         }
 92         wrv=fwrite(buf,1,rv,fo);
 93         if (wrv!=rv) {
 94             fclose(fo);
 95             _close(fh);
 96             printf("fwrite %s error\n",ofn);
 97             return;
 98         } else {
 99             offs+=rv;
100             cprintf("%I64u\r",offs);
101             if (offs>=offs1) break;//
102         }
103     }
104     fclose(fo);
105     _close(fh);
106     printf("Copy %s offset %s to %s OK.\n",argv[1],argv[2],ofn);
107 }