Re: How to lseek the larger file > 2GB under linux

[Nicle <ynicle@gmail.com>]

Hi all,

 I have a file > 2GB, and my job is seeking the file to pos: 2.1G.
But, it seems that the lseek64 doesn't work.
Here is the sample code:

#define _LARGEFILE64_SOURCE
#include ...

int main()
{
 int fd = -1;
 long long pos = (long long) 2*1024*1024*1024 + 10; // over 2G

 fd = open(FILENAME, O_WRONLY|O_LARGEFILE);
 if (fd < 0){
   ...
 }

 if (lseek64(fd, pos, SEEK_SET) < 0) {
     fprintf(stderr, "Failed seeking to %lld, %s\n", pos, strerror(errno));
 }

 return 0;
}

 Then the building cmd:
    gcc -o test test.c -D_FILE_OFFSET_BITS=64

 Output:
    Failed seeking to 2147483658, Success.

The return val of lseek64  was "<0", but the strerror told me "Success".