03-24-2019
You are jumping the gun at the moment; UNDERSTAND what is going on first!
I mentioned that there is a FLAW. Try to understand that when messing with HW you need to know what you are doing.
Read the URL and understand to get a grasp of what is going on; although the code will work 99.999% of the time there is a condition known as a "race condition".
Race condition - Wikipedia
Although not strictly a race condition it is a _pseudo_race condition.
An explanation:
If you move the mouse a tiny fraction of a second AFTER the 'if' line and before the condition is finalised then the two variables will be the same.
Assuming you have this _polling_ as you put it in a loop then this will be missed on the second variable and the next time in the loop the two values will be the same again and so it will seem no-one has moved the mouse. This, although NOT strictly a race condition per-se is close enough.
AFAIAC there is no easy cure using sequential code like a shell script so you HAVE to be aware of such situations.
So be aware; it is these subtleties that can cause headaches in the future.
As for _polling_ you could put the code inside a 'while' loop,
while true and exit the loop via a
break command using the conditional statement if that is what you want.
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~
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LEARN ABOUT HPUX
pthread_condattr_init
pthread_condattr_init(3T) pthread_condattr_init(3T)
NAME
pthread_condattr_init(), pthread_condattr_destroy() - initialize or destroy a condition variable attributes object.
SYNOPSIS
PARAMETERS
attr Pointer to the condition variable attributes object to be initialized or destroyed.
DESCRIPTION
initializes the condition variable attributes object attr with the default values for all attributes. The attributes object describes a
condition variable in detail and is passed to the condition variable initialization function.
When a condition variable attributes object is used to initialize a condition variable, the values of the individual attributes determine
the characteristics of the new condition variable. Attributes objects act like additional parameters to object initialization. A single
attributes object can be used in multiple calls to the function
When a condition variable is initialized with an attributes object, the attributes are, in effect, copied into the condition variable.
Consequently, any change to the attributes object will not affect any previously initialized condition variables. Once all condition vari-
ables needing a specific attributes object have been initialized, the attributes object is no longer needed.
The condition variable attributes and their default values are:
The default value is
If an initialized condition variable attributes object is reinitialized, undefined behavior results.
destroys the condition variable attributes object attr. The destroyed condition variable attributes object ceases to exist and its
resources are reclaimed. Using attr after it has been destroyed results in undefined behavior. A destroyed condition variable attributes
object can be reinitialized using the function
Condition variables that have been already initialized using this attributes object are not affected by the destruction of the condition
variable attributes object.
RETURN VALUE
Upon successful completion, and return zero. Otherwise, an error number is returned to indicate the error (the variable is not set).
ERRORS
If any of the following occur, the function returns the corresponding error number:
[ENOMEM] There is insufficient memory available in which to initialize the condition variable attributes object.
[EINVAL] attr is not a valid condition variable attributes object.
For each of the following conditions, if the condition is detected, the function returns the corresponding error number:
[EINVAL] attr is not a valid condition variable attributes object.
AUTHOR
and were derived from the IEEE POSIX P1003.1c standard.
SEE ALSO
pthread_create(3T), pthread_condattr_getpshared(3T), pthread_cond_init(3T).
STANDARDS CONFORMANCE
Pthread Library pthread_condattr_init(3T)