Date: Thu, 27 Jul 2000 15:22:01 +0300 From: Dimitar Peikov <mitko@rila.bg> To: hackers@FreeBSD.ORG Subject: mmap syncs and file extends Message-ID: <00072715314205.05330@earth>
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Hi, hackers,
I've try to use mmap() and resize the mapping. msync() syncronizes only t=
he
memory that was mmapped with mmap(). How can I extend the main file? Memo=
ry is
filled correctly, but I must write extended data to file by hand.
In my examples 'x.txt' was 11 bytes (some text); Where I'm wrong?
----------
#include <unistd.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
=20
int main() {
char *ptr;
int fd, size=3D20;
=20
fd =3D open("x.txt", O_RDWR | O_CREAT);
ptr =3D mmap(0, 15, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
ptr[0] =3D 'D';
ptr[6] =3D 'D';
ptr =3D mremap(ptr, 10, 20, 1);
close(fd);
ptr[10] =3D 'Y';
ptr[12] =3D 'X';
printf("1%C\n", ptr[12]);
msync(ptr, size, MS_SYNC);
munmap(ptr, size);
}
----------
--=20
Dimitar Peikov
Programmer
"We Build e-Business" =20
RILA Solutions =20
27 Building, Acad.G.Bonchev Str. =20
1113 Sofia, Bulgaria =20
home: (+359 2) 595495
phone: (+359 2) 9797320=20
phone: (+359 2) 9797300=20
fax: (+359 2) 9733355 =20
http://www.rila.com=20
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