A question of fork() function

[bite me if you can...]

The man page of fork() says that the file descriptor are shared by
parent process & childern processes, so any operation of file
descriptor will affect them both.
But why the behavior of FILE doesn't like file descriptors?

This is my program, the result of operation of file descriptor is
ideal, but result of operation of FILE is amazing...
int fd=-1, pid;
FILE *fin=(FILE *)NULL;

fd=open("mem.tmp", O_RDWR);
fin=fopen("mem1.tmp", "r");
pid=fork();
if(pid) {
printf("(parent)\n");
printf("(parent) lseek(): %d\n", lseek(fd, 10, SEEK_SET));
fseek(fin, 10, SEEK_SET);
printf("(parent) ftell(): %d\n", ftell(fin));
}
else {
printf("(child)\n");
printf("(child)\n");
printf("(child) ftell(): %d\n", ftell(fin));
}

[Artie Gold]

bite me if you can... wrote:

The man page of fork() says that the file descriptor are shared by
parent process & childern processes, so any operation of file

[snip]

....news:comp.unix.programmer, where things like fork() are *on*-topic.

HTH,
--ag

--
Artie Gold -- Austin, Texas
http://goldsays.blogspot.com
"You can't KISS* unless you MISS**"
[*-Keep it simple, stupid. **-Make it simple, stupid.]

[Keith Thompson]

"bite me if you can..." <cc*****@gmail.com> writes:

The man page of fork() says

[...]

fork(), like mmap(), is not a standard C function. Try
comp.unix.programmer.

--
Keith Thompson (The_Other_Keith) ks***@mib.org <http://www.ghoti.net/~kst>
San Diego Supercomputer Center <*> <http://users.sdsc.edu/~kst>
We must do something. This is something. Therefore, we must do this.

[SM Ryan]

"bite me if you can..." <cc*****@gmail.com> wrote:
# The man page of fork() says that the file descriptor are shared by
# parent process & childern processes, so any operation of file
# descriptor will affect them both.
# But why the behavior of FILE doesn't like file descriptors?

FILEs aren't file descriptors. They have additional buffering
and other attributes. If you want to multitask, like fork or
threads, you need to check your system's documentation how these
interact with stdio.

--
SM Ryan http://www.rawbw.com/~wyrmwif/
I love the smell of commerce in the morning.