wait

How to wait for a keypress in R?

由 本秂侑毒 提交于 2019-11-26 06:16:58
问题 I want to pause my R script until the user presses a key. How do I do this? 回答1: As someone already wrote in a comment, you don't have to use the cat before readline() . Simply write: readline(prompt="Press [enter] to continue") If you don't want to assign it to a variable and don't want a return printed in the console, wrap the readline() in an invisible() : invisible(readline(prompt="Press [enter] to continue")) 回答2: Method 1 Waits until you press [enter] in the console: cat ("Press [enter]

Why are wait() and notify() declared in Java's Object class?

由 我怕爱的太早我们不能终老 提交于 2019-11-26 06:00:04
问题 Why are the wait() and notify() methods declared in the Object class, rather than the Thread class? 回答1: Because, you wait on a given Object (or specifically, its monitor) to use this functionality. I think you may be mistaken on how these methods work. They're not simply at a Thread-granularity level, i.e. it is not a case of just calling wait() and being woken up by the next call to notify() . Rather, you always call wait() on a specific object, and will only be woken by calls to notify on

Difference between WAIT and BLOCKED thread states

由 ╄→尐↘猪︶ㄣ 提交于 2019-11-26 04:59:13
问题 What is the difference between thread state WAIT and thread state BLOCKED? The Thread.State documentation: Blocked A thread that is blocked waiting for a monitor lock is in this state. Waiting A thread that is waiting indefinitely for another thread to perform a particular action is in this state does not explain the difference to me. 回答1: A thread goes to wait state once it calls wait() on an Object. This is called Waiting State. Once a thread reaches waiting state, it will need to wait till

Wait for a process to finish

由 耗尽温柔 提交于 2019-11-26 04:30:23
问题 Is there any builtin feature in Bash to wait for a process to finish? The wait command only allows one to wait for child processes to finish. I would like to know if there is any way to wait for any process to finish before proceeding in any script. A mechanical way to do this is as follows but I would like to know if there is any builtin feature in Bash. while ps -p `cat $PID_FILE` > /dev/null; do sleep 1; done 回答1: To wait for any process to finish Linux: tail --pid=$pid -f /dev/null Darwin

How do I make python to wait for a pressed key

由 若如初见. 提交于 2019-11-26 03:18:34
问题 I want my script to wait until the user presses any key. How do I do that? 回答1: In Python 3, no raw_input() exists. So, just use: input("Press Enter to continue...") In Python 2, you should use raw_input() , as input(prompt) is equivalent to eval(raw_input(prompt)) : raw_input("Press Enter to continue...") This only waits for a user to press enter though, so you might want to use msvcrt ((Windows/DOS only) The msvcrt module gives you access to a number of functions in the Microsoft Visual C/C

How to wait in bash for several subprocesses to finish and return exit code !=0 when any subprocess ends with code !=0?

由 和自甴很熟 提交于 2019-11-26 03:14:01
问题 How to wait in a bash script for several subprocesses spawned from that script to finish and return exit code !=0 when any of the subprocesses ends with code !=0 ? Simple script: #!/bin/bash for i in `seq 0 9`; do doCalculations $i & done wait The above script will wait for all 10 spawned subprocesses, but it will always give exit status 0 (see help wait ). How can I modify this script so it will discover exit statuses of spawned subprocesses and return exit code 1 when any of subprocesses

Is there a decent wait function in C++?

由 旧时模样 提交于 2019-11-26 03:10:08
问题 One of the first things I learned in C++ was that #include <iostream> int main() { std::cout<<\"Hello, World!\\n\"; return 0; } would simply appear and disappear extremely quickly without pause. To prevent this, I had to go to notepad, and save helloworld.exe pause ase helloworld.bat This got tedious when I needed to create a bunch of small test programs, and eventually I simply put while(true); at the end on most of my test programs, just so I could see the results. Is there a better wait

JavaScript sleep/wait before continuing [duplicate]

由 ℡╲_俬逩灬. 提交于 2019-11-26 02:50:55
This question already has an answer here: What is the JavaScript version of sleep()? 74 answers I have a JavaScript code that I need to add a sleep/wait function to. The code I am running is already in a function, eg: function myFunction(time) { alert('time starts now'); //code to make the program wait before continuing alert('time is up') } I have heard that a possible solution might include setTimeout but I am not sure how to use it in this case. I can't use PHP, as my server does not support it, although using jQuery would be fine. BeNdErR JS does not have a sleep function, it has

How to wait for a number of threads to complete?

由 寵の児 提交于 2019-11-26 01:13:27
问题 What is a way to simply wait for all threaded process to finish? For example, let\'s say I have: public class DoSomethingInAThread implements Runnable{ public static void main(String[] args) { for (int n=0; n<1000; n++) { Thread t = new Thread(new DoSomethingInAThread()); t.start(); } // wait for all threads\' run() methods to complete before continuing } public void run() { // do something here } } How do I alter this so the main() method pauses at the comment until all threads\' run()

JavaScript sleep/wait before continuing [duplicate]

由 我与影子孤独终老i 提交于 2019-11-26 01:11:29
问题 This question already has an answer here: What is the JavaScript version of sleep()? 75 answers I have a JavaScript code that I need to add a sleep/wait function to. The code I am running is already in a function, eg: function myFunction(time) { alert(\'time starts now\'); //code to make the program wait before continuing alert(\'time is up\') } I have heard that a possible solution might include setTimeout but I am not sure how to use it in this case. I can\'t use PHP, as my server does not
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