Question

I use FTP to list the file attributes on the server. I request the name of file and put them into an array. I print the array directly like this:

NSLog(@"%@", array); 

What I got is like this:

\U6587\U4ef6\U540d\Uff1afilename.txt
\U6587\U4ef6\U540d\Uff1afilename1.txt
......

When I want to print the Unicode “\U6587\U4ef6\U540d\Uff1a” to see what it is, I got the compiling error: “incomplete universal character name”.

However, If I print the name instead of the whole array, I can get the name correctly without the Unicode. But I need to do something with the name in the array. I want to know why the Unicode is there, and is it proper to just remove the Unicode then to do something with the real file name?

Answer 1

In C99, and therefore presumably Objective C too, there are two Unicode escapes:

\uXXXX
\UXXXXXXXX

The lower-case u is followed by 4 hex digits; the upper-case U is followed by 8 hex digits (of which, the first two should be zeroes to be valid Unicode (and the third should be 0 or 1; the maximum Unicode code point is U+10FFFF).

I believe that if you replace the upper-case U‘s with lower-case u‘s, you should get the code to compile.

On my Mac OS 10.7.4 system, compiling with GCC 4.7.0 (home built), I compiled this code:

#include <stdio.h>

int main(void)
{
    char array[] = "\u6587\u4ef6\u540d\uff1a";
    puts(array);
    return 0;
}

and got this output:

• 文件名：

I can’t answer why the characters are there, but the colon-like character at the end suggests that the site might be preceding the actual file name with a tag of some sort (analogous to ‘file:’).