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mprotect |
Portability: | UNIX compatible |
SYNOPSIS | |
DESCRIPTION | |
RETURN VALUE | |
USAGE NOTES | |
EXAMPLE | |
RELATED FUNCTIONS |
SYNOPSIS |
#include <mman.h> int mprotect(void *addr, unsigned int len, int prot);
DESCRIPTION |
The
mprotect
function is used to
change the protection status of one or more pages of memory mapped to an HFS
file by a previous call to the
mmap
function.
The
addr
argument
is the address of the first page of mapped memory for which the protection
attributes are to be changed. The address must be on a page boundary, but
need not be the first byte of the entire area mapped to a file.
The
len
argument
specifies the number of bytes of memory whose protection attributes are to
be changed. If the length does not specify an integral number of pages, it
is rounded up to do so. The length need not specify the entire area of mapped
memory.
The
prot
argument
specifies the new protection status of the mapped memory. It should be specified
as one of the symbolic constants described in the
mmap
function write-up.
You cannot specify
PROT_WRITE
if the file descriptor for the file does not permit writing.
Note: See the IBM UNIX
System Services Assembler Callable Services
manual for additional information about the behavior of
mprotect
and the conditions under which it can
be used.
RETURN VALUE |
mprotect
returns
0
if successful,
or
-1
if unsuccessful.
USAGE NOTES |
The
mprotect
function can only be used with MVS 5.2.2 or a later release.
EXAMPLE |
Refer to mmap for an example.
RELATED FUNCTIONS |
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Copyright © 2001 by SAS Institute Inc., Cary, NC, USA. All rights reserved.