Description
int
shmop_open
( int key, string flags, int mode, int size)
shmop_open(
)
can
create
or
open
a
shared
memory
block
.
shmop_open(
)
takes
4
parameters
:
key
,
which
is
the
system
's
id
for
the
shared
memory
block
,
this
parameter
can
be
passed
as
a
decimal
or
hex
.
The
second
parameter
are
the
flags
that
you
can
use
:
-
"
a
"
for
access
(sets
IPC_EXCL
)
use
this
flag
when
you
need
to
open
an
existing
shared
memory
segment
-
"
c
"
for
create
(sets
IPC_CREATE
)
use
this
flag
when
you
need
to
create
a
new
shared
memory
segment
.
The third parameter is the mode, which are the permissions that
you wish to assign to your memory segment, those are the same as
permission for a file. Permissions need to be passed in octal
form ex. 0644. The last parameter is size of the shared memory
block you wish to create in bytes.
Nota
:
Note
:
the
3rd
and
4th
should
be
entered
as
0
if
you
are
opening
an
existing
memory
segment
.
On
success
shmop_open(
)
will
return
an
id
that
you
can
use
to
access
the
shared
memory
segment
you
've
created
.
Ejemplo
1
.
Create
a
new
shared
memory
block
?php
$shm_id
=
shmop_open(
0x0fff
,
"c"
,
0644
,
100)
;
?
|
|
This
example
opened
a
shared
memory
block
with
a
system
id
of
0x0fff
.