From: tad.bochan@...
Date: 2004-08-26T20:53:15+09:00
Subject: Dereferencing pointers returned by syscall


Hi,

I'm using 'syscall' in ruby to access the 'mmap'  function in Unix (HPUX),
to try to read/write a memory-mapped file.
The 'mmap' function returns a pointer to the mapped file.
I can't figure out how I am supposed to be able to use
this pointer  to access the data from ruby.

PROT-NONE         = 0
PROT-USER         = 0
PROT-READ         = 1
PROT-WRITE        = 2
MAP-SHARED        = 1
prot=PROT_READ | PROT_WRITE
flags=MAP_SHARED
len=1024
ofs=0
mmfptr=syscall(71, 0,  prot, flags, filedes, ofs)

mmfptr is now  a pointer to a 1024 byte structure.

How can I  get ruby to access this structure ?

Regards,

Tad.   (ruby,perl,unix newbie)





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