Date: Thu, 6 Apr 2006 08:56:46 +0200 (CEST) From: Wojciech Puchar <wojtek@tensor.3miasto.net> To: Dan Nelson <dnelson@allantgroup.com> Cc: freebsd-questions@freebsd.org Subject: Re: programmer questions - MMAP Message-ID: <20060406085436.T33354@chylonia.3miasto.net> In-Reply-To: <20060405214304.GG32089@dan.emsphone.com> References: <20060405231726.W81334@chylonia.3miasto.net> <20060405214304.GG32089@dan.emsphone.com>
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>>
>> #include <sys/mman.h>
>> #include <fcntl.h>
>> #include <stdio.h>
>> #include <unistd.h>
>> main() {
>> int ff=open("test",O_RDWR|O_CREAT,0666);
>> char *adr;
>> lseek(ff,1<<24,0);
>> write(ff,"",1);
>> adr=mmap(0,1<<24,PROT_READ|PROT_WRITE,MAP_NOCORE,ff,0);
>
> Try MAP_NOCORE|MAP_SHARED here. It's probably defaulting to a private
> mapping.
WORKS!!! thank you.
another question - do i need to create 16MB hole to be able to write
directly up to 16MB data. it would be nice if mmap is able to extend the
file as needed without lseek/write. is it possible?
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