_ftruncate64 on large files?

[drhoule]

I am dealing with long files...
I can use _ftruncate on short files but not long ones.

_ftruncate uses a long int.

a long long int is required.

How can I code / use _ftruncate with long files?

Any help would be nice.

Thank you in advance!
Dr.

[frankie]

Dindn't understand the question.
_ftruncate uses an _off_t type that is a long long.
The function doesn't care of the size of the file. You can use it on short and large files.

[TimoVJL]

_ftruncate uses an _off_t type that is a long long.

just in x64

sys\types.h

Code Select Expand

#if __POCC_TARGET__ == 3
typedef long long _off_t;
#else
typedef long _off_t;

[drhoule]

More info,

MS VC has this function ...
     errno_t   _chsize_s(  int fd, __int64 size );
                  but it is not implemented with Pelles C only int _chsize(int handle, long int size);

Dr

[frankie]

Try this:

Code Select Expand


#include <stdio.h>
#include <io.h>

BOOL SetFileLength(int fd, long long pos)
{
HANDLE fh = (HANDLE)_get_osfhandle(fd);
if (!SetFilePointerEx(fh, *((LARGE_INTEGER *)&pos), NULL, FILE_BEGIN))
return FALSE;

return SetEndOfFile(fh);
}

BOOL fset_file_len(FILE *fp, long long pos)
{
return SetFileLength(_fileno(fp), pos);
}

I had no time to test, but should work.

[drhoule]

Your solution looks good.

I accept this as a reasonable fix.

I will test it and or modify it as needed, in the comming months as I work on this small project.

Thank you.

[drhoule]

Tested. Confirmed!

Your proposed solution is good.
Thank you very much.

Dr

[frankie]

Good 
You're welcome

[zohanx747]

I will test it and or modify it as needed, in the comming months as I work on this small project.