C中特殊字符文件的读写
使用 C 语言，我尝试操作 openssl 生成的一些文件，其中包含很多（非常）特殊字符。但文件结尾似乎被过早检测到。 例如，请参阅我的程序的摘录，该摘录应该将一个文件复制到另一个文件：（
为了简单起见，我没有显示打开文件的测试，但我在我的程序中这样做）
char msgcrypt[FFILE];
FILE* fMsg = fopen(f4Path,"r");
while(fgets(tmp,FFILE,fMsg) != NULL) strcat(msgcrypt,tmp);
fclose(fMsg);
FILE* fMsg2 = fopen(f5Path,"w");
fprintf(fMsg2,"%s",msgcrypt);
fclose(fMsg2);
这是文件的内容位于 f4Path ：
Salted__X¢~xÁïÈú™xe^„fl¯�˜<åD
现在是位于 f5Path 的文件内容：
Salted__X¢~xÁïÈú™xe^„fl¯
请注意，缺少 4 个字符。
有人有主意吗？
Using the C language, I am trying to manipulate some files generated by openssl and containing a lot of (very) special characters. But the end of file seems to be prematurely detected.
For example see an extract of my program, that is supposed to copy a file to another :
(for simplicity reasons I do not show the test of the opening of the file but I do that in my program)
char msgcrypt[FFILE];
FILE* fMsg = fopen(f4Path,"r");
while(fgets(tmp,FFILE,fMsg) != NULL) strcat(msgcrypt,tmp);
fclose(fMsg);
FILE* fMsg2 = fopen(f5Path,"w");
fprintf(fMsg2,"%s",msgcrypt);
fclose(fMsg2);
here is the content of the file located at f4Path :
Salted__X¢~xÁïÈú™xe^„fl¯�˜<åD
now the content of the file located at f5Path :
Salted__X¢~xÁïÈú™xe^„fl¯
Notice that 4 characters are missing.
Do someone have an idea?
如果你对这篇内容有疑问，欢迎到本站社区发帖提问 参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。
绑定邮箱获取回复消息
由于您还没有绑定你的真实邮箱，如果其他用户或者作者回复了您的评论，将不能在第一时间通知您！
发布评论
评论（3）
听起来很熟悉。
fopen(f4Path, "rb")。这对于 Windows 来说具有真正的意义。fprintf、strcat、fgets等），它们会因NUL字符而阻塞。请改用fread和fwrite。Sounds familiar.
fopen(f4Path, "rb")when opening the file. This has real significance on Windows.fprintf,strcat,fgetsetc) they will choke onNULcharacters. Usefreadandfwriteinstead.strcat尝试复制一个以 null 结尾的char *。这意味着，如果它遇到 0（它可能已经在这里完成了），它将停止复制。你最好使用
open、read、memcpy和write。strcattries and copy a nul-terminatedchar *. Which means, if it encounters a 0, which it probably has done here, it will stop copying.You'd better use
openread,memcpyandwrite.我把它停在的那个字符复制到十六进制编辑器中，如果我没记错的话，它最终会变成 EF BF BD，一个 BOM。因此，将文件作为文本文件读取失败。我没有看到任何 NULL 字符（除非复制和粘贴删除了它们）。
答案（正如已经讨论过的）是不要将其视为文本文件，并且避免使用 str 函数也不会造成任何损害。
我要做的第一件事是添加一个检查，检查字符的读取方式，这样您就知道数据在哪里被截断。现在它可以是以下任何一个：read、strcat、write。
That character it stops on I copied into a hex editor, and it ends up being EF BF BD, a BOM if I'm not mistaken. As a result, reading the file as a text file fails. I don't see any NULL characters (unless copying and pasting got rid of them).
The answer (as has already been discussed) is to not treat it as a text file, and avoiding the str functions won't do any harm either.
The first thing I'd do though is add a check for how may characters are read, that way you'll know where the data is being truncated. Right now it could be in any of: read, strcat, write.