Hi Michal,
The "LL" does make my prog work :)
Thanks for your help!!
Best Regard
Nicle Yang
>
>
> 2009/5/18 Michal Nazarewicz <mina86@xxxxxxx>
>>
>> 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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