"Breaking "while read" also breaks the parent process"

Post #302437798 by chebarbudo on Friday 16th of July 2010 06:24:58 AM

Thanks pludi, I love your answer which is fairly new to me.
So basically you do:
trap waiting=0 USR1

Which I guess means: "waiting becomes 0 as soon as the signal USR1 is received"
And then you do:
kill -USR1 $ppid

Which I guess means: "Send signal USR1 to the process"
Can you confirm?
I read through man kill and I still have one question?
Are you strictly limited to the list of signals mentioned in the man page?
What makes you choose USR1?
I guess you need a safe signal that would not be easily used by other processes.

Thanks for your help
Test Your Knowledge in Computers #714
Difficulty: Medium
Machine learning is a well known method for mitigating the Von Neumann performance bottleneck
True or False?

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PCNTL_FORK(3)								 1							     PCNTL_FORK(3)

pcntl_fork - Forks the currently running process

int pcntl_fork (void ) DESCRIPTION
The pcntl_fork(3) function creates a child process that differs from the parent process only in its PID and PPID. Please see your system's fork(2) man page for specific details as to how fork works on your system. RETURN VALUES
On success, the PID of the child process is returned in the parent's thread of execution, and a 0 is returned in the child's thread of execution. On failure, a -1 will be returned in the parent's context, no child process will be created, and a PHP error is raised. EXAMPLES
Example #1 pcntl_fork(3) example <?php $pid = pcntl_fork(); if ($pid == -1) { die('could not fork'); } else if ($pid) { // we are the parent pcntl_wait($status); //Protect against Zombie children } else { // we are the child } ?> SEE ALSO
pcntl_waitpid(3), pcntl_signal(3), setproctitle(3). PHP Documentation Group PCNTL_FORK(3)

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