Nicle <ynicle@xxxxxxxxx> writes:
> 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.
> #define _LARGEFILE64_SOURCE
> #include ...
>
> int main() {
> int fd = -1;
> long long pos = (long long) 2*1024*1024*1024 + 10; // over 2G
A long shot, but try (2LL << 30) (the "LL" is important). I don't
expect that will make it work but if you're out of ideas... ;)
> 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".
BTW. The following works fine for me:
#v+
#define _LARGEFILE64_SOURCE
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#define RUN(expr) if ((expr) < 0) { perror(#expr); return 1; } else (void)0
int main(void) {
const long long pos = (2LL << 30) + 10;
int fd;
RUN(fd = open("deleteme", O_WRONLY | O_LARGEFILE | O_CREAT, 0600));
RUN(lseek64(fd, pos, SEEK_SET));
RUN(write(fd, "a", 1));
return 0;
}
#v-
--
Best regards, _ _
.o. | Liege of Serenly Enlightened Majesty of o' \,=./ `o
..o | Computer Science, Michal "mina86" Nazarewicz (o o)
ooo +--<mina86*tlen.pl>--<jid:mina86*jabber.org>--ooO--(_)--Ooo--
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