I am learning how to use the threading and the multiprocessing modules in Python to run certain operations in parallel and speed up my code. I am finding this hard (maybe because I don’t have any theoretical background about it) to understand what the difference is between a threading.Thread() object and a multiprocessing.Process() one. Also, … Read more
What’s the most efficient way to trim the suffix in Java, like this: title part1.txt title part2.html => title part1 title part2 22 Answers 22
when I run ps -aux command on my linux server, to which I connected using putty, few processes are too long to fit in my current window width. Is there an alternative? — Update — I am sorry for downgrading,I thought others won’t find the answer useful too, so I downgraded. Here is the info … Read more
What’s a quick-and-dirty way to make sure that only one instance of a shell script is running at a given time? 41 Answers 41 Use flock(1) to make an exclusive scoped lock a on file descriptor. This way you can even synchronize different parts of the script. #!/bin/bash ( # Wait for lock on /var/lock/.myscript.exclusivelock … Read more
What exactly are process and update in PrimeFaces p:commandXxx components and execute and render in f:ajax tag? Which works at the time of validation? What does update attribute do rather than updating value to component from back end? Do process attribute bind value to model? What exactly do @this, @parent, @all and @form in both … Read more
In a bash script, I want to do the following (in pseudo-code): if [ a process exists with $PID ]; then kill $PID fi What’s the appropriate expression for the conditional statement? 11 Answers 11
I’d like to run an external process and capture it’s command output to a variable in PowerShell. I’m currently using this: $params = “/verify $pc /domain:hosp.uhhg.org” start-process “netdom.exe” $params -WindowStyle Hidden -Wait I’ve confirmed the command is executing but I need to capture the output into a variable. This means I can’t use the -RedirectOutput … Read more
Suppose I have a process which spawns exactly one child process. Now when the parent process exits for whatever reason (normally or abnormally, by kill, ^C, assert failure or anything else) I want the child process to die. How to do that correctly? Some similar question on stackoverflow: (asked earlier) How can I cause a … Read more
I’ve an application which does Process.Start() to start another application ‘ABC’. I want to wait till that application ends (process dies) and continue my execution. How can I do it? There may be multiple instances of the application ‘ABC’ running at the same time. 9 Answers 9
I was looking to find the difference between these four on Google and I expected there to be a huge amount of information on this, but there really wasn’t any solid comparison between the four calls. I set about trying to compile a kind of basic at-a-glance look at the differences between these system calls … Read more
