If you&#39;re using a version of Ubuntu prior to 19.04, you&#39;ll need to install **libmysql-java**, the MySQL JDBC driver, because the connector is not in the Ubuntu-packaged MySQL package that you&#39;ve already installed. Versions after that do not publish that package.

Once it&#39;s installed, you&#39;ll have the file `/usr/share/java/mysql.jar`, which is an indirect symlink to the actual jar file.

Alternatively, install the [mysql-apt-config](https://dev.mysql.com/downloads/repo/apt/) package, update, and you&#39;ll be able to install all currently supported MySQL software with `apt`.

First, `apt-get install libmysql-java`

Then `mysql.jar` is located in `/usr/share/java/mysql.jar`.

Third, in Eclipse, do this as: Project -&gt; Properties -&gt; Java Build Path -&gt; Libraries -&gt; Add External JARs -&gt; select `/usr/share/java/mysql.jar`

In ubuntu 19.10 the following works:


    apt-get install libmariadb-java



I have followed some Facebook API 3.0 tutorials, including the Login/Logout and the Publish To Feed examples. So the login works this way:

1. App opens, shows a fragment which displays a login button
2. User clicks login, the authentication is done via the referenced FacebookSDK library (com.facebook.widget.LoginActivity) and the provided code using sessions.
3. User is redirected to next screen

I don&#39;t want to make the user to login this way. I want them to use my app without any login/registration, then if they click on a facebook specific feature e.g. share a note on Facebook, then the app should ask them whether they let Facebook use their app or something, you know the usual stuff. Without this I get a nullpointer in the publishFeedDialog() function as session is null, because no login has been made.

So my question is, how can I ignore the SplashFragment with the Login button, so when the user clicks on a Facebook feature in my app, no new screen is displayed with a login button, but only the default Facebook authentication window that users are used to?

Facebook authentication without login button

I need to turn a list of last names into alphanumeric usernames, however unfortunately some of them contain non-ascii characters:

    Hern&#225;ndez
    Querman&#231;&#243;s 
    Miguel&#225;&#241;ez

Now one way would just to use a regex to remove any non-alpha numeric characters such as `a.replace(/[^a-z0-9]/gi,&#39;&#39;)`. However a more intuitive solution (at least for the user) would be to replace accented characters with their &quot;plain&quot; equivalent, e.g. turn `&#225;`, `&#225;` into `a`, and `&#231;` into `c`, etc. Is there an easy way to do this in javascript?

Replacing accented characters with plain ascii ones

I have installed MySQL 5.5.32 via `apt-get install` into Ubuntu 13.04.I want to use it in a Java project.For this i must have MySql connector jar.I can not find it.I tried `locate *mysql*.jar` but it did not find anything.I looked into `/etc/mysql` but there is no jar in it.**I don&#39;t want to download it from internet** because i believe that it somehow exists in an MySQL folder.Does anybody have any idea where the connector jar went into Ubuntu 13.04?

Where is the MySQL JDBC jar file in Ubuntu?

<p>I have installed MySQL 5.5.32 via <code>apt-get install</code> into Ubuntu 13.04.I want to use it in a Java project.For this i must have MySql connector jar.I can not find it.I tried <code>locate *mysql*.jar</code> but it did not find anything.I looked into <code>/etc/mysql</code> but there is no jar in it.<strong>I don't want to download it from internet</strong> because i believe that it somehow exists in an MySQL folder.Does anybody have any idea where the connector jar went into Ubuntu 13.04?</p>


I installed Xampp on Windows 7 32-bit. When I try to start MySql in XAMPP control panel (v3.2.1) I have the following message and MySql does not start.

    23:02:03  [mysql] 	Problem detected!
    23:02:03  [mysql] 	Port 3306 in use by &quot;&quot;C:\Program Files\MySQL\MySQL Server 5.1\bin\mysqld&quot; --defaults-file=&quot;C:\Program Files\MySQL\MySQL Server 5.1\my.ini&quot; MySQL&quot;!
    23:02:03  [mysql] 	MySQL WILL NOT start without the configured ports free!
    23:02:03  [mysql] 	You need to uninstall/disable/reconfigure the blocking application
    23:02:03  [mysql] 	or reconfigure MySQL and the Control Panel to listen on a different port
    23:02:03  [mysql] 	Attempting to start MySQL service...

A similar problem was reported [here](https://stackoverflow.com/questions/17377027/why-is-mysql-and-xampp-not-starting) but there is no working answer. When I try to install with MySql disabled, the result is that I even don&#39;t have an option even to try to run it.

I am new to Xampp and don&#39;t know where and what to look for to solve the issue

I need to run Apache and MySql with Php.




xampp MySQL does not start

I have problem when executing this code:

    SELECT * FROM tblpm n 
    WHERE date_updated=(SELECT MAX(date_updated) 
    FROM tblpm GROUP BY control_number 
    HAVING control_number=n.control_number)

Basically, I want to return the most recent date for each control number. The query above returns correct output but it takes 37secs. before the output was shown.

Is there any other sql clause or command that can execute faster than the query above?

Thanks in advance.


GROUP BY having MAX date

I was recently asked this question in an interview.
I tried this in mySQL, and got the same results(final results).
All gave the number of rows in that particular table.
Can anyone explain the major difference between them.

What is the difference between count(0), count(1).. and count(*) in mySQL/SQL?

I&#39;m using Sequelize in my Nodejs project and I found a problem that I&#39;m having a hard time to solve.
Basically I have a cron that gets an array of objects from a server than inserts it on my database as a object ( for this case, cartoons ). But if I already have one of the objects, I have to update it.

Basically I have a array of objects and a could use the BulkCreate() method. But as the Cron starts again, it doesn&#39;t solve it so I was needing some sort of update with an upsert true flag. And the main issue: I must have a callback that fires just once after all these creates or updates. Does anyone have an idea of how can I do that? Iterate over an array of object.. creating or updating it and then getting a single callback after?

Thanks for the attention 

Create or Update Sequelize

So I read the other posts but this question is unique. So this SQL dump file has this as the last entry.

    INSERT INTO `wp_posts` VALUES(2781, 3, &#39;2013-01-04 17:24:19&#39;, &#39;2013-01-05 00:24:19&#39;.

I&#39;m trying to insert this value to the table...

    INSERT INTO `wp_posts` VALUES(5, 5, &#39;2005-04-11 09:54:35&#39;, &#39;2005-04-11 17:54:35&#39;

it gives me the error, &quot;Column count doesn&#39;t match value count at row 1.&quot; So I&#39;m lost on the concept of how the column and row apply here. 

Doesn&#39;t `2781,3` mean row 2781 and column 3? And doesn&#39;t `5,5` mean row 5 and column 5?


Column count doesn&#39;t match value count at row 1

The x86-64 System V ABI (used on everything except Windows) used to live at http://x86-64.org/documentation/abi.pdf, but that site has now fallen off the internet.

Is there a new authoritative home for the document?


Where is the x86-64 System V ABI documented?

I would like to have the equivelant of the following in a one line if/else condition.

    $maxline=`cat journald.conf | grep &quot;#SystemMaxUse=&quot;`
    if [ $maxline == &quot;#SystemMaxUse=&quot; ]
    then
        sed &#39;s/\#SystemMaxUse=/SystemMaxUse=50M/g&#39; journald.conf &gt; journald.conf2
        mv journald.conf2 journald.conf;
    else
        echo &quot;This file has been edited. You&#39;ll need to do it manually.&quot;
    fi  

I&#39;m attempting to put this into a one line command. So far I&#39;ve gotten it all but the else portion of the command. Here&#39;s what I have so far...

    maxline=`cat journald.conf | grep &quot;#SystemMaxUse=&quot;` &amp;&amp; if [ $maxline == &quot;#SystemMaxUse=&quot; ]; then sed &#39;s/\#SystemMaxUse=/SystemMaxUse=50M/g&#39; journald.conf &gt; journald.conf2 &amp;&amp; mv journald.conf2 journald.conf; fi

So how can I include the else portion of the above code into my command? Thank you for your help in advance.

  


One line if/else condition in linux shell scripting

I want to subtract &quot;number of days&quot; from a date in bash. I am trying something like this ..

    echo $dataset_date #output is 2013-08-07

    echo $date_diff #output is 2   
 
    p_dataset_date=`$dataset_date --date=&quot;-$date_diff days&quot; +%Y-%m-%d` # Getting Error



subtract days from a date in bash

I thought I understood *nix pipes until now... I have an executable called `studio` which symlinks to my install of `Android Studio` and I had assumed I could get the linked-to location with 

    which studio | ls -l

But that doesn&#39;t work. What it gives me is equivalent to having just run `ls -l` in the current directory.

If I run `which studio`, I get `/home/me/bin/studio`. And if I run `ls -l /home/me/bin/studio` I get the expected output showing me the symlink location.

So why doesn&#39;t the piped version work? What haven&#39;t I grokked about pipes?

Unix pipe into ls

I have a string in the following format:

`string1:string2:string3:string4:string5`

I&#39;m trying to use `sed` to split the string on `:` and print each sub-string on a new line.  Here is what I&#39;m doing:

`cat ~/Desktop/myfile.txt | sed s/:/\\n/` 

This prints:

    string1
    string2:string3:string4:string5

How can I get it to split on each delimiter?



Using sed to split a string with a delimiter

I installed nodejs on ubuntu from instructions given [here][1]

When I write `node --version` in the terminal I see this : &lt;br&gt;
`-bash: /usr/sbin/node: No such file or directory`

I can see node in the `/usr/sbin/` directory, though.

Writing `npm --version` shows `1.3.5` &lt;br&gt;
Writing `nodejs --version` shows `v0.10.15`

Also, I can see node in the `/usr/bin/` directory.

So, how do I get `node` working?

Also, If I use *zsh* instead of bash, then `node` command works.

  [1]: https://github.com/joyent/node/wiki/Installing-Node.js-via-package-manager#ubuntu-mint

nodejs vs node on ubuntu 12.04

Apache is logging `PHP Fatal error:  Call to undefined function json_decode()`. After some googling, it seems this problem is a result of not having the latest version of php. Oddly, running `php --version` ouputs 

    PHP 5.5.1-2+debphp.org~precise+2 (cli) (built: Aug  6 2013 10:49:43) 
    Copyright (c) 1997-2013 The PHP Group
    Zend Engine v2.5.0, Copyright (c) 1998-2013 Zend Technologies
        with Zend OPcache v7.0.2-dev, Copyright (c) 1999-2013, by Zend Technologies
        with Xdebug v2.2.3, Copyright (c) 2002-2013, by Derick Rethans
Clearly showing that my `php` version is greater than `5.1`. 

Any ideas as to what could cause this, or the steps to take to find out?

EDIT: The result of a script echoing phpversion is `5.5.1-2+debphp.org~precise`

EDIT: The result of `phpinfo()` is also `PHP Version 5.5.1-2+debphp.org~precise+2`

Furthermore, in the `phpinfo()`, it lists the module JSON and the module authors (Omar Kilani, Scott MacVicar).

PHP Fatal error: Call to undefined function json_decode()

I just installed `screen` and like the idea to divide linux terminal into multiple pieces. But I can&#39;t figure out one thing: How to scroll up and down, when I&#39;m in `screen`. When I&#39;m using regular linux terminal I can achieve this with &lt;kbd&gt;Shift&lt;/kbd&gt; + &lt;kbd&gt;Pg Up&lt;/kbd&gt; or &lt;kbd&gt;Shift&lt;/kbd&gt; + &lt;kbd&gt;Pg Dn&lt;/kbd&gt;`. but unfortunatelly it doesn&#39;t work in divided terminal.

That&#39;s what I mean when saying `screen` and divided terminal:
![enter image description here][1]


And that&#39;s a regular termina (just in case):
![enter image description here][2]


  [1]: http://i.stack.imgur.com/0N9vH.png
  [2]: http://i.stack.imgur.com/586le.png

How to scroll up and down in sliced &quot;screen&quot; terminal

When I restart the nginx service on a command line on an Ubuntu server, the service crashes when a nginx configuration file has errors. On a multi-site server this puts down all the sites, even the ones without configuration errors.

To prevent this, I run the nginx configuration test first:

    nginx -t

After the test ran successful, I could restart the service:

    /etc/init.d/nginx restart

**Or** only reload the nignx site configs without a restart:

    nginx -s reload

Is there a way to combine those two commands where the restart command is conditional to the configuration test&#39;s result?

I couldn&#39;t find this online and [the official documentation][1] on this is rather basic. I don&#39;t know my way around Linux that well, so I don&#39;t know if what I&#39;m looking for is right in front of me or not possible at all.

I&#39;m using nginx v1.1.19.

  [1]: http://wiki.nginx.org/CommandLine



How do I restart nginx only after the configuration test was successful on Ubuntu?

I am getting the &quot;No space left on device&quot; error for pretty much anything i try to do. Even using tab to autocomplete a command!

but when i do df -h i get:

    ubuntu@ip-10-0-2-108:~$ df -h
    Filesystem      Size  Used Avail Use% Mounted on
    /dev/xvda1       99G  6.5G   88G   7% /
    udev            3.7G  8.0K  3.7G   1% /dev
    tmpfs           1.5G  184K  1.5G   1% /run
    none            5.0M     0  5.0M   0% /run/lock
    none            3.7G     0  3.7G   0% /run/shm
    none            100M     0  100M   0% /run/user
    /dev/xvdb       414G  199M  393G   1% /mnt
    overflow        1.0M  1.0M     0 100% /tmp

which to me looks like there is tons of space. df -i also looks similar:

    ubuntu@ip-10-0-2-108:~$ df -i
    Filesystem       Inodes IUsed    IFree IUse% Mounted on
    /dev/xvda1      6553600 94227  6459373    2% /
    udev             951353   393   950960    1% /dev
    tmpfs            953649   274   953375    1% /run
    none             953649     3   953646    1% /run/lock
    none             953649     1   953648    1% /run/shm
    none             953649     1   953648    1% /run/user
    /dev/xvdb      27525120    11 27525109    1% /mnt
    overflow         953649    12   953637    1% /tmp

I am on an Amazon EC2 ubuntu 12.04 instance.

Here are some examples of the error popping up:

    ubuntu@ip-10-0-2-108:~$ sudo crontab -e
    /tmp/crontab.RvYjrR/crontab: No space left on device

    ubuntu@ip-10-0-2-108:~$ ls /va (hit tab for autocomplete)
    
    -bash: cannot create temp file for here-document: No space left on device
    -bash: cannot create temp file for here-document: No space left on device

however the server seems to be running and everything seems to be working.
what on earth is going on??




Content Type	Original Author	Original Content on Stackoverflow
Question	ihsan kocak	View Question on Stackoverflow
Solution 1 - Mysql	Jeremy Smyth	View Answer on Stackoverflow
Solution 2 - Mysql	wangzhengyi	View Answer on Stackoverflow
Solution 3 - Mysql	koe	View Answer on Stackoverflow

Where is the MySQL JDBC jar file in Ubuntu?

Mysql Problem Overview

Mysql Solutions

Solution 1 - Mysql

Solution 2 - Mysql

Solution 3 - Mysql

Replacing accented characters with plain ascii ones

Facebook authentication without login button

Attributions