As new processes fork in, PIDs will increase to a system-dependent limit and then wrap around. The kernel will not reuse a PID before this wrap-around happens.

The limit (maximum number of pids) is `/proc/sys/kernel/pid_max`. [The manual][1] says:

&gt; `/proc/sys/kernel/pid_max` (since Linux 2.5.34)
&gt;
&gt; This file specifies the value at which **PIDs wrap around** (i.e., the
&gt; value in this file is one greater than the maximum PID).  The default
&gt; value for this file, `32768`, results in the same range of PIDs as on
&gt; earlier kernels


  [1]: http://www.kernel.org/doc/man-pages/online/pages/man5/proc.5.html

https://superuser.com/questions/135007/how-are-pids-generated

This should answer your question - it appears it will recycle PIDs when it runs out, skipping the ones that are still assigned.

I have experience in coding OpenMP for Shared Memory machines (in both C and FORTRAN) to carry out simple tasks like matrix addition, multiplication etc. (Just to see how it competes with LAPACK). I know OpenMP enough to carry out simple tasks without the need to look at documentation.

Recently, I shifted to Python for my projects and I don&#39;t have any experience with Python beyond the absolute basics.

My question is :

What is the *easiest* way to use OpenMP in Python? By easiest, I mean the one that takes least effort on the programmer side (even if it comes at the expense of added system time)?

The reason I use OpenMP is because a serial code can be converted to a working parallel code with a few `!$OMP`s scattered around. The time required to achieve a _rough_ parallelization is fascinatingly small. Is there any way to replicate this feature in Python?

From browsing around on SO, I can find:

- C extensions
- StackLess Python

Are there more? Which aligns best with my question?

OpenMP and Python

I take user-input (JS code) and execute (process) them in realtime to show some output.

Sometimes the code has those zero-width spaces; it&#39;s really weird. I don&#39;t know how the users are inputting that. Example: `&quot;(​$&quot;.length === 3`

I need to be able to remove that character from my code in JS. How do I do so? or maybe there&#39;s some other way to execute that JS code so that the browser doesn&#39;t take the zero-width space characters into account?

Remove zero-width space characters from a JavaScript string

Is there any policy in Linux as to the recycling of used PIDs ? I mean, if a PId has been used, how much later will it be used again ?

Linux PID recycling

<p>Is there any policy in Linux as to the recycling of used PIDs ? I mean, if a PId has been used, how much later will it be used again ?</p>


I have been searching for a command that will return files from the current directory which contain a string in the filename. I have seen `locate` and `find` commands that can find files beginning with something `first_word*` or ending with something `*.jpg`. 

How can I return a list of files which contain a string in the filename? 

For example, if `2012-06-04-touch-multiple-files-in-linux.markdown` was a file in the current directory. 

How could I return this file and others containing the string `touch`? Using a command such as `find &#39;/touch/&#39;`

Find all files with name containing string

When we debug a program using `gdb`, we usually see functions with strange names defined in `libc`(`glibc`?). My questions are:

1. Is `libc/glibc` the standard implementation of some standard C/C++ functions like `strcpy`,`strlen`,`malloc`?
2. Or, is it not only of the first usage as described above, but also an wrapper of Unix/Linux system calls like `open`,`close`,`fctl`? If so, why can&#39;t we issue syscalls directly, without `libc`?
3. Does `libc` only consist of one lib (`.a` or `.so`) file, or many lib files (in this case, `libc` is the general name of this set of libs)? Where do these lib file(s) reside?
4. What is the difference between `libc` and `glibc`?

What is the role of libc(glibc) in our linux app?

I need to replace a string in a lot of files in a folder, with only `ssh` access to the server. How can I do this?

How to replace a string in multiple files in linux command line

Whenever I try to push into my repo git asks for both `username &amp; password`. 

I have no problem in re-entering my password each time but the problem is in entering username. I use `https` to clone my repository.

So, how can I configure git so that it doesn&#39;t asks for `username` on each `git push`.

I am new to linux but IIRC in windows `git push` only asks for password.


Git asks for username every time I push

I have as simple function in a bash script and I would like to pipe stdout to it as an input.
 
    jc_hms(){
      printf &quot;$1&quot;
    }

I&#39;d like to use it in this manner.

    var=`echo &quot;teststring&quot; | jc_hms`

Of course I used redundant functions echo and printf to simplify the question, but you get the idea.  Right now I get a &quot;not found&quot; error, which I assume means my parameter delimiting is wrong (the &quot;$1&quot; part).  Any suggestions?

Originally the jc_hms function was used like this:

    echo `jc_hms &quot;teststring&quot;` &gt; //dev/tts/0

but I&#39;d like to store the results in a variable for further processing first, before sending it to the serial port.

EDIT:
So to clarify, I am NOT trying to print stuff to the serial port, I&#39;d like to interface to my bash functions should the &quot;|&quot; pipe character, and I am wondering if this is possible.

EDIT: Alright, here&#39;s the full function.

    jc_hms(){
      hr=$(($1 / 3600))
      min=$(($1 / 60))
      sec=$(($1 % 60))
    
      printf &quot;$hs:%02d:%02d&quot; $min $sec
    }

I&#39;m using the function to form a string which come this line of code

    songplaytime=`echo $songtime | awk &#39;{print S1 }&#39;`
    printstring=&quot;`jc_hms $songplaytime`&quot;  #store resulting string in printstring

Where $songtime is a string expressed as &quot;playtime totaltime&quot; delimited by a space.

I wish I can just do this in one line, and pipe it after the awk

    printstring=`echo $songtime | awk &#39;{print S1 }&#39; | jc_hms`

like so.

Pipe output to bash function

Anyone has experienced this problem?
Yesterday I still can run my app in simulator but now I cannot run my app since Xcode prints this error in console:

    error: failed to attach to process ID &lt;ID number&gt;

[![Screenshot for error][1]][1]

I have tried to reinstall, do this [post][2] and create new project but returns no luck.
Anyone can resolve this issue?

I use Xcode 4.5 Preview 2 and try to run iOS simulator 6


  [1]: http://i.stack.imgur.com/FzEfO.png
  [2]: https://stackoverflow.com/questions/10323481/thread-1-stopped-at-breakpoint-1/10323839#10323839

Failed to Attach to Process ID Xcode

I am writing a script to monitor the CPU and MEM of any given process. For that i need to send in the name of the process to be monitored as a commandline argument. For example. 

    ./monitorscript &lt;pname&gt;

I need to get the pid of the process in the script so that i can use a `ps -p &lt;pid&gt;` inside. 

How do i get the pid of a process given its process name? 

I understand that there might be multiple processes in the same name. I just want to get the first process out of that list. 



How to get the PID of a process by giving the process name in Mac OS X ?

I am having an issue where MySQL isn&#39;t starting on my QNAP NAS.

I found this first by not being able to log in through phpMyAdmin - was getting error: 

    #2002 Cannot log in to the MySQL server

I then went to attempt to start mysql, as I guess this is a common issue with this, but it just gave a generic error.

I went through troubleshooting the mysql.sock file and everything, changing its permissions, but nothing is working.

I have rebooted my NAS many times.

I eventually tried to restart mysql.  In doing so I get:

    ERROR! MySQL manager or server PID file could not be found!

I can&#39;t find anything specific to the QNAP or any general type troubleshooting for this.  Everything I find seems to be OSX related.

ERROR! MySQL manager or server PID file could not be found! QNAP

  
By using &quot;ucbps&quot; command i am able to get all PIDs


 

     $ ucbps
      
       Userid     PID     CPU %  Mem %  FD Used   Server                  Port
       =========================================================================
          
       512        5783    2.50   16.30  350       managed1_adrrtwls02     61001
       512        8896    2.70   21.10  393       admin_adrrtwls02        61000
       512        9053    2.70   17.10  351       managed2_adrrtwls02     61002




I want to do it like this, but don&#39;t know how to do

1. variable=get pid of process by processname.
2. Then use this command kill -9 variable.


How to get PID of process by specifying process name and store it in a variable to use further?

I ve installed Postgresql and then ran a bunch of rails apps on my local Mac OSX Mountain Lion and created databases etc. Today after a while when I launched pgAdminIII and tried to launch a database server I got this error:

![enter image description here][1]


A quick google showed [this][2] post. More browsing pointed to the fact that there might be some sort of postmaster.pid file lying around that might be the root cause of this. If I delete that things would be fine.

However, before I go deleting stuff on my computer I wanted to make sure Im debugging this in a systematic way which would not result in more problems.

Somewhere I read that before deleting that file, I need to run this command:

      ps auxw | grep post

If I get no results then, its OK to delete the file. Else not. Well, I got this result of that command:

      AM               476   0.0  0.0  2423356    184 s000  R+    9:28pm   0:00.00 grep post



So now of course Im throughly confused. 

So what should I do?

Here is part of my postgres server error log:

     FATAL:  lock file &quot;postmaster.pid&quot; already exists
     HINT:  Is another postmaster (PID 171) running in data directory &quot;/usr/local/var/postgres&quot;?


Postgresql is still not running, still get the same error and nothing has changed. Im too chicken to delete things without checking on SO.

Could some of you experts please guide a noob.




Thanks


  [1]: http://i.stack.imgur.com/hOsJd.png
  [2]: https://stackoverflow.com/questions/8465508/can-not-connect-to-local-postgresql

Postgres DB not starting on Mac OSX: ERROR says: connections on Unix domain socket

Canvas: trying to use a recycled bitmap android.graphics.Bitmap in Android

I&#39;m using `RecyclerView` inside `NestedScrollView`. Also i set `setNestedScrollingEnabled` to false for `recyclerview`


**to support lower API** 

`ViewCompat.setNestedScrollingEnabled(mRecyclerView, false);`



Now! When user scrolled the view every thing seems okay, but!!! views in recyclerview does not recycled!!! and Heap size grows swiftly!!

**Update**:
RecyclerView layout manager is `StaggeredLayoutManager`

**fragment_profile.xml**:

    &lt;android.support.design.widget.CoordinatorLayout
        xmlns:android=&quot;http://schemas.android.com/apk/res/android&quot;
        xmlns:app=&quot;http://schemas.android.com/apk/res-auto&quot;
        xmlns:tools=&quot;http://schemas.android.com/tools&quot;
        android:id=&quot;@+id/coordinator&quot;
        android:layout_width=&quot;match_parent&quot;
        android:layout_height=&quot;match_parent&quot;
        android:orientation=&quot;vertical&quot; &gt;

            &lt;android.support.design.widget.AppBarLayout
                android:id=&quot;@+id/appbar&quot;
                android:layout_width=&quot;match_parent&quot;
                android:layout_height=&quot;wrap_content&quot;
                android:theme=&quot;@style/ThemeOverlay.AppCompat.Dark.ActionBar&quot; &gt;
            &lt;/android.support.design.widget.AppBarLayout&gt;

            &lt;android.support.v4.widget.SwipeRefreshLayout
                android:id=&quot;@+id/profileSwipeRefreshLayout&quot;
                android:layout_width=&quot;match_parent&quot;
                android:layout_height=&quot;match_parent&quot; &gt;

                    &lt;!-- RecyclerView and NestedScrollView --&gt;
                    &lt;include layout=&quot;@layout/fragment_profile_details&quot; /&gt;

            &lt;/android.support.v4.widget.SwipeRefreshLayout&gt;

    &lt;/android.support.design.widget.CoordinatorLayout&gt;


**fragment_profile_details.xml**:

    &lt;LinearLayout
        xmlns:android=&quot;http://schemas.android.com/apk/res/android&quot;
        xmlns:app=&quot;http://schemas.android.com/apk/res-auto&quot;
        xmlns:tools=&quot;http://schemas.android.com/tools&quot;
        android:id=&quot;@+id/rootLayout&quot;
        android:layout_width=&quot;match_parent&quot;
        android:layout_height=&quot;match_parent&quot;
        app:layout_behavior=&quot;@string/appbar_scrolling_view_behavior&quot;
        android:orientation=&quot;vertical&quot; &gt;

            &lt;android.support.v4.widget.NestedScrollView
                android:id=&quot;@+id/nested_scrollbar&quot;
                android:layout_width=&quot;match_parent&quot;
                android:layout_height=&quot;match_parent&quot;
                android:layout_gravity=&quot;fill_vertical&quot;
                app:layout_behavior=&quot;@string/appbar_scrolling_view_behavior&quot;
                android:fillViewport=&quot;true&quot;
                android:scrollbars=&quot;none&quot; &gt;

                    &lt;LinearLayout
                        android:id=&quot;@+id/nested_scrollbar_linear&quot;
                        android:layout_width=&quot;match_parent&quot;
                        android:layout_height=&quot;wrap_content&quot;
                        android:descendantFocusability=&quot;blocksDescendants&quot;
                        android:orientation=&quot;vertical&quot; &gt;

                            &lt;android.support.v7.widget.CardView
                                android:id=&quot;@+id/profileCardview&quot;
                                android:layout_width=&quot;match_parent&quot;
                                android:layout_height=&quot;wrap_content&quot;
                                app:cardBackgroundColor=&quot;@color/card_backgroind&quot;
                                app:cardCornerRadius=&quot;0dp&quot;
                                app:cardElevation=&quot;0dp&quot; &gt;

                                &lt;!-- Profile related stuff like avatar and etc. ---&gt;

                            &lt;/android.support.v7.widget.CardView&gt;

                            &lt;android.support.v7.widget.RecyclerView
                                android:id=&quot;@+id/list_view&quot;
                                android:layout_width=&quot;match_parent&quot;
                                android:layout_height=&quot;wrap_content&quot;
                                android:layout_marginBottom=&quot;@dimen/four&quot;
                                android:layout_marginEnd=&quot;@dimen/four&quot;
                                android:layout_marginLeft=&quot;@dimen/four&quot;
                                android:layout_marginRight=&quot;@dimen/four&quot;
                                android:layout_marginStart=&quot;@dimen/four&quot;
                                android:layout_marginTop=&quot;@dimen/four&quot;
                                app:layout_behavior=&quot;@string/appbar_scrolling_view_behavior&quot;
                                android:clipToPadding=&quot;false&quot; /&gt;

                    &lt;/LinearLayout&gt;
            &lt;/android.support.v4.widget.NestedScrollView&gt;
    &lt;/LinearLayout&gt;


**ProfileFragment.java**:

    mAdapter		= new MainAdapter(getActivity(), glide, Data);
	
	listView		= (RecyclerView) view.findViewById(R.id.list_view);

	ViewCompat.setNestedScrollingEnabled(listView, false);	
	listView.setAdapter(mAdapter);
	
	mStaggeredLM	= new StaggeredGridLayoutManager(2, StaggeredGridLayoutManager.VERTICAL);
	mStaggeredLM.setGapStrategy(StaggeredGridLayoutManager.GAP_HANDLING_MOVE_ITEMS_BETWEEN_SPANS);
	
	listView.setLayoutManager(mStaggeredLM);
		
	mScroll.setOnScrollChangeListener(new OnScrollChangeListener() {
			
			@Override
			public void onScrollChange(NestedScrollView arg0, int arg1, int arg2, int arg3, int arg4) {
                
				View view	= (View) mScroll.getChildAt(mScroll.getChildCount() - 1);
				int diff	= (view.getBottom() - ( mScroll.getHeight() + mScroll.getScrollY()));
				
				if(diff == 0){
					
					int visibleItemCount			= mStaggeredLM.getChildCount();
					int totalItemCount				= mStaggeredLM.getItemCount();
					
					int[] lastVisibleItemPositions	= mStaggeredLM.findLastVisibleItemPositions(null);
					int lastVisibleItemPos	= getLastVisibleItem(lastVisibleItemPositions);

					Log.e(&quot;getChildCount&quot;, String.valueOf(visibleItemCount));
	                Log.e(&quot;getItemCount&quot;, String.valueOf(totalItemCount));
	                Log.e(&quot;lastVisibleItemPos&quot;, String.valueOf(lastVisibleItemPos));
	                
	                if ((visibleItemCount + 5) &gt;= totalItemCount) {
	                
	                	mLoadMore.setVisibility(View.VISIBLE);
	                    Log.e(&quot;LOG&quot;, &quot;Last Item Reached!&quot;);
	                }
	                
					mMore = true;
					mFresh = false;
					mRefresh = false;
					getPosts();
				}
				
			}
			
		});

P.s : I&#39;ve set load more to scroll view, because `recyclerview` do it continuously and none stoppable!  

Any help is appreciated

Content Type	Original Author	Original Content on Stackoverflow
Question	Cygnus	View Question on Stackoverflow
Solution 1 - Linux	cnicutar	View Answer on Stackoverflow
Solution 2 - Linux	Osmium USA	View Answer on Stackoverflow

Linux PID recycling

Linux Problem Overview

Linux Solutions

Solution 1 - Linux

Solution 2 - Linux

Remove zero-width space characters from a JavaScript string

OpenMP and Python

Attributions