06-30-2006
hpux does not have mandatory locking - that means every process that opens the file has to play by the rules. So, if you lock your file, then run another program that does not play by those rules, the lock will not work. It's like obeying a traffic light. Some people break the rules and do not stop on red. There is no physical barrier to stop them - a physical barrier at a traffic light is like manadtory locking. They cannot run the red light/They can't play with the file no matter what
Please show your code.
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plock(3C) Standard C Library Functions plock(3C)
NAME
plock - lock or unlock into memory process, text, or data
SYNOPSIS
#include <sys/lock.h>
int plock(int op);
DESCRIPTION
The plock() function allows the calling process to lock or unlock into memory its text segment (text lock), its data segment (data lock),
or both its text and data segments (process lock). Locked segments are immune to all routine swapping. The effective user ID of the calling
process must be super-user to use this call.
The plock() function performs the function specified by op:
PROCLOCK Lock text and data segments into memory (process lock).
TXTLOCK Lock text segment into memory (text lock).
DATLOCK Lock data segment into memory (data lock).
UNLOCK Remove locks.
RETURN VALUES
Upon successful completion, 0 is returned. Otherwise, -1 is returned and errno is set to indicate the error.
ERRORS
The plock() function fails and does not perform the requested operation if:
EAGAIN Not enough memory.
EINVAL The op argument is equal to PROCLOCK and a process lock, a text lock, or a data lock already exists on the calling process; the op
argument is equal to TXTLOCK and a text lock or a process lock already exists on the calling process; the op argument is equal to
DATLOCK and a data lock or a process lock already exists on the calling process; or the op argument is equal to UNLOCK and no lock
exists on the calling process.
EPERM The {PRIV_PROC_LOCK_MEMORY} privilege is not asserted in the effective set of the calling process.
USAGE
The mlock(3C) and mlockall(3C) functions are the preferred interfaces for process locking.
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|MT-Level |MT-Safe |
+-----------------------------+-----------------------------+
SEE ALSO
exec(2), exit(2), fork(2), memcntl(2), mlock(3C), mlockall(3C), attributes(5)
SunOS 5.10 22 Mar 2004 plock(3C)