One simple thing you could do is abstract the test inside a function.

    local function isempty(s)
      return s == nil or s == &#39;&#39;
    end

    if isempty(foo) then
      foo = &quot;default value&quot;
    end

&gt; Can this code be simplified in one if test instead two?

`nil` and `&#39;&#39;` are different values. If you need to test that `s` is neither, IMO you should just compare against both, because it makes your intent the most clear.

That and a few alternatives, with their generated bytecode:

    if not foo or foo == &#39;&#39; then end
         GETGLOBAL       0 -1    ; foo
         TEST            0 0 0
         JMP             3       ; to 7
         GETGLOBAL       0 -1    ; foo
         EQ              0 0 -2  ; - &quot;&quot;
         JMP             0       ; to 7

    if foo == nil or foo == &#39;&#39; then end
        GETGLOBAL       0 -1    ; foo
        EQ              1 0 -2  ; - nil
        JMP             3       ; to 7
        GETGLOBAL       0 -1    ; foo
        EQ              0 0 -3  ; - &quot;&quot;
        JMP             0       ; to 7

    if (foo or &#39;&#39;) == &#39;&#39; then end
       GETGLOBAL       0 -1    ; foo
       TEST            0 0 1
       JMP             1       ; to 5
       LOADK           0 -2    ; &quot;&quot;
       EQ              0 0 -2  ; - &quot;&quot;
       JMP             0       ; to 7

The second is fastest in Lua 5.1 and 5.2 (on my machine anyway), but difference is tiny. I&#39;d go with the first for clarity&#39;s sake.


why doesn&#39;t this work I am trying to change all files to 644 abd all -d to 755:

    find . -type f -exec chmod 644 {} ;

**i get: find: missing argument to `-exec&#39;**
 thanks

find . -type f -exec chmod 644 {} ;

I&#39;m trying to learn Python and decided to use PyCharm.  When I try to start a new project I get a dialog that says &quot;No Python interpreter selected&quot;.  It has a drop down to select a interpreter, but the drop down is empty.

Trying to get PyCharm to work, keep getting &quot;No Python interpreter selected&quot;

I&#39;ve some currently some Lua code using the following syntax:

    if (foo == nil or foo == &#39;&#39;) then
        foo = &quot;some default value&quot;
    end
 
The goal of the if condition is to test foo is neither an empty string, neither a nil value.

Can this code be simplified in one if test instead two?

Check if a string isn&#39;t nil or empty in Lua

I've some currently some Lua code using the following syntax:
<pre><code class="hljs language-ini">if (foo == nil or foo == '') then
 foo = "some default value"
end
</code></pre>
The goal of the if condition is to test foo is neither an empty string, neither a nil value.
Can this code be simplified in one if test instead two?

I find myself repeatedly writing the same chunk of code:

	def stringInList(str, list):
		retVal = False
		for item in list:
			if str in item:
				retVal = True
		return retVal

Is there any way I can write this function quicker/with less code?
I usually use this in an if statement, like this:

    if stringInList(str, list):
        print &#39;string was found!&#39;

Simplest way of checking for string that contains a string in list?

My whole script is currently this:

    #!/bin/sh   
    clear;   
    blanko=&quot;&quot;;   
    # Dummy-Variablen
    variable=Testvariable;   
    if [[$variable == $blanko]];
    then   
      echo &quot;Nichts da!&quot;   
    else   
      echo $variable   
    fi
    
and if I enter 

    TestSelect.sh

I get

    /usr/bin/TestSelect.sh: line 6: [[Testvariable: command not found   
    Testvariable

How can I fix this?

Getting &quot;command not found&quot; error while comparing two strings in Bash

I found [this][1].

And I am trying this:

    x=&#39;some
       thing&#39;

    y=(${x//\n/})

And I had no luck, I thought it could work with double backslash:

    y=(${x//\\n/})

But it did not.

To test I am not getting what I want I am doing:

    echo ${y[1]}

Getting:

    some
    thing

Which I want to be:

    some

I want `y` to be an array `[some, thing]`. How can I do this?


  [1]: https://stackoverflow.com/a/5257398/1197775

Split bash string by newline characters

For what function I can use in android to display the number into different formats.

For eg: 
If I enter 1000 then it should display like this 1,000.
If I enter 10000 then it should display like this 10,000.
If I enter 1000000 then it should display like this 1,000,000.

Please guide me.




How can I format a String number to have commas in android Edit Field

I&#39;m new to awk and sed, and I&#39;m looking for a way to truncate a line at 80 characters, but I&#39;m printing several strings in that line using printf. The last two strings are the ones that give me problems because they vary in size on each iteration of my code. Here&#39;s my current code:

    printf &quot;%5d  %3s%.2s %4s %s %s \n&quot; &quot;$f&quot; &quot;$month&quot; &quot;$day&quot; &quot;$year&quot; &quot;$from&quot; &quot;$subject&quot;

This code is being used to create a summary of email messages that get passed through a Bash script. What I do know, is that with the spaces and requirements of my other strings, I have room for 60 characters between the $from and $subject strings.

Any help is appreciated.

Multiple strings, Truncate line at 80 characters

This is a question I&#39;ve been mildly irritated about for some time and just never got around to search the answer to.

However I thought I might at least ask the question and perhaps someone can explain.

Basically many languages I&#39;ve worked in utilize syntactic sugar to write (using syntax from C++):

    int main() {
        int a = 2;
        a += 3; // a=a+3
    }

while in lua the `+=` is not defined, so I would have to write `a=a+3`, which again is all about syntactical sugar. when using a more &quot;meaningful&quot; variable name such as: `bleed_damage_over_time` or something it starts getting tedious to write: 

    bleed_damage_over_time = bleed_damage_over_time + added_bleed_damage_over_time 

instead of: 

    bleed_damage_over_time += added_bleed_damage_over_time

So I would like to know not how to solve this if you don&#39;t have a nice solution, in that case I would of course be interested in hearing it; but rather why lua doesn&#39;t implement this syntactical sugar.


Lua operators, why isn&#39;t +=, -= and so on defined?

Many will found that this is repeating questions but i have gone through all the questions before asked about this topic but none worked for me.

I want to print full path name of the certain file format using ls command so far i found chunk of code that will print all the files in the directory but not full path.


    for i in io.popen(&quot;ls /mnt/mediashare/net/192.168.1.220_STORAGE_1d1b7&quot;):lines() do
      if string.find(i,&quot;%.*$&quot;) then 
         print(i) 
      end
    end

this will print out all the file in root diractory and subdiratory.

Output:

      0020111118223425.lvf
      2012
      2012 (2009).mp4
      3 Idiots
      Aashiqui 2
      Agneepath.mkv
      Avatar (2009)
      Captain Phillips (2013)
      Cocktail
      
  
I want output like:

      /mnt/mediashare/net/192.168.1.220_STORAGE_1d1b7/0020111118223425.lvf           [File in Root Directory]
      /mnt/mediashare/net/192.168.1.220_STORAGE_1d1b7/2012/2012.mkv
      /mnt/mediashare/net/192.168.1.220_STORAGE_1d1b7/2012 (2009).mp4                [File in Root Directory]
      /mnt/mediashare/net/192.168.1.220_STORAGE_1d1b7/3 Idiots/3 Idiots.mkv
      /mnt/mediashare/net/192.168.1.220_STORAGE_1d1b7/Aashiqui 2/Aashiqui 2.mkv
      /mnt/mediashare/net/192.168.1.220_STORAGE_1d1b7/Avatar (2009)/Avatar (2009).mkv
      /mnt/mediashare/net/192.168.1.220_STORAGE_1d1b7/Captain Phillips (2013).mkv
      /mnt/mediashare/net/192.168.1.220_STORAGE_1d1b7/Cocktail/Cocktail.mkv
    

**EDIT:**
I have used this all but its not working with my code in LUA.

when I used with my code it displays wrong directory

    for i in io.popen(&quot;ls -d $PWD/* /mnt/mediashare/net/192.168.1.220_STORAGE_1d1b7&quot;):lines() do
        if string.find(i,&quot;%.*$&quot;) then
          print(&quot;/mnt/mediashare/net/192.168.1.220_STORAGE_1d1b7/&quot;..i)
        end
      end

is not finding files in &quot;/mnt/mediashare/net/192.168.1.220_STORAGE_1d1b7&quot; insted its prints the machines root directory files.
    


List file using ls command in Linux with full path

I&#39;m trying to figure out the equivalent of:

    foo = []
    foo &lt;&lt; &quot;bar&quot;
    foo &lt;&lt; &quot;baz&quot;

I don&#39;t want to have to come up with an incrementing index. Is there an easy way to do this?

How do I append to a table in Lua

I need a Torch command that checks if two tensors have the same content, and returns TRUE if they have the same content.

For example:

    local tens_a = torch.Tensor({9,8,7,6});
    local tens_b = torch.Tensor({9,8,7,6});
    
    if (tens_a EQUIVALENCE_COMMAND tens_b) then ... end

What should I use in this script instead of `EQUIVALENCE_COMMAND` ?

I tried simply with `==` but it does not work. 

How to check if two Torch tensors or matrices are equal?

I have a game project to re-implement [Breakout](https://en.wikipedia.org/wiki/Breakout_(video_game)). I want to display two words, each word on a line. They are joined by the bricks block. Inside, the top line is the first name, aligned left. The bottom line is the last name, aligned right. They are input from textboxes, and rendered as shown:

![As described above][1]

Each second that passes, the screen will add a configurable number of bricks to the grid (for example, five bricks per second) until the two words appear complete. I displayed a letter of the alphabet which is created from the matrix(0,1). 

...But I don’t know how to join them into one word. **How can I join these letters?**

This is what I&#39;ve gotten so far:

###Bricks.lua


    local Bricks = display.newGroup() -- static object
	local Events = require(&quot;Events&quot;)
	local Levels = require(&quot;Levels&quot;)
	local sound = require(&quot;Sound&quot;)
	local physics = require(&quot;physics&quot;)
	local Sprites = require(&quot;Sprites&quot;)
	local Func = require(&quot;Func&quot;)


	local brickSpriteData = 
	{
		{
			name = &quot;brick&quot;,
			frames = {Sprites.brick}
		},

		{
			name = &quot;brick2&quot;,
			frames = {Sprites.brick2}
		},

		{
			name = &quot;brick3&quot;,
			frames = {Sprites.brick3}
		},

	}

	-- animation table
	local brickAnimations = {}

	Sprites:CreateAnimationTable
	{
		spriteData = brickSpriteData,
		animationTable = brickAnimations
	}

	-- get size from temp object for later use
	local tempBrick = display.newImage(&#39;red_apple_20.png&#39;,300,500)
	--local tempBrick = display.newImage(&#39;cheryGreen2.png&#39;,300,500)
	local brickSize =
	{
		width = tempBrick.width, 
		height = tempBrick.height
	}
	--tempBrick:removeSelf( )


	----------------
	-- Rubble -- needs to be moved to its own file
	----------------

	local rubbleSpriteData =
	{
		{
			name = &quot;rubble1&quot;,
			frames = {Sprites.rubble1}
		},

		{
			name = &quot;rubble2&quot;,
			frames = {Sprites.rubble2}
		},

		{
			name = &quot;rubble3&quot;,
			frames = {Sprites.rubble3}
		},

		{
			name = &quot;rubble4&quot;,
			frames = {Sprites.rubble4}
		},

		{
			name = &quot;rubble5&quot;,
			frames = {Sprites.rubble5}
		},

	}

	local rubbleAnimations = {}
	Sprites:CreateAnimationTable
	{
		spriteData = rubbleSpriteData,
		animationTable = rubbleAnimations
	}

	local totalBricksBroken = 0 -- used to track when level is complete
	local totalBricksAtStart = 0

	-- contains all brick objects
	local bricks = {}


	local function CreateBrick(data)

		-- random brick sprite
		local obj = display.newImage(&#39;red_apple_20.png&#39;)
		local objGreen = display.newImage(&#39;cheryGreen2.png&#39;)
		obj.name = &quot;brick&quot;
		obj.x = data.x --or display.contentCenterX
		obj.y = data.y --or 1000
		obj.brickType = data.brickType or 1
		obj.index = data.index

		function obj:Break()
		
			totalBricksBroken =  totalBricksBroken + 1
			bricks[self.index] = nil
			obj:removeSelf( )
			sound.play(sound.breakBrick)

		end

		function obj:Update()
			if(self == nil) then
				return
			end 

			if(self.y &gt; display.contentHeight - 20) then
				obj:Break()
			end 
		end 
		if(obj.brickType ==1) then
			physics.addBody( obj, &quot;static&quot;, {friction=0.5, bounce=0.5 } )
		elseif(obj.brickType == 2) then
		 	physics.addBody( objGreen,&quot;static&quot;,{friction=0.2, bounce=0.5, density = 1 } )
		end 

		return obj
	end

	local currentLevel = testLevel
	-- create level from bricks defined in an object
	-- this allows for levels to be designed
	local function CreateBricksFromTable(level)

		totalBricksAtStart = 0
		local activeBricksCount = 0
		for yi=1, #level.bricks do
			for xi=1, #level.bricks[yi] do
				-- create brick?
				if(level.bricks[yi][xi] &gt; 0) then
					local xPos
					local yPos
					if(level.align == &quot;center&quot;) then
						--1100-((99*16)*0.5)
						xPos = display.contentCenterX- ((level.columns * brickSize.width) * 0.5/3) + ((xi-1) * level.xSpace)--display.contentCenterX 
						--xPos = 300 +(xi * level.xSpace)
						yPos = 100 + (yi * level.ySpace)--100
					else
						xPos = level.xStart + (xi * level.xSpace)
						yPos = level.yStart + (yi * level.ySpace)
					end

					local brickData = 
			  		{
				 		x = xPos,
						y = yPos,
						brickType = level.bricks[yi][xi],
						index = activeBricksCount+1
					}
					bricks[activeBricksCount+1] = CreateBrick(brickData)
				
					activeBricksCount = activeBricksCount + 1

				end

			end 

		end
		
		totalBricks = activeBricksCount
		totalBricksAtStart = activeBricksCount


	end

	-- create bricks for level --&gt; set from above functions, change function to change brick build type
	local CreateAllBricks = CreateBricksFromTable
	-- called by a timer so I can pass arguments to CreateAllBricks
	local function CreateAllBricksTimerCall()
		CreateAllBricks(Levels.currentLevel)
	end 
	-- remove all brick objects from memory
	local function ClearBricks()

		for i=1, #bricks do
			bricks[i] = nil
		end

	end
	-- stuff run on enterFrame event
	function Bricks:Update()

	-- update individual bricks
		if(totalBricksAtStart &gt; 0) then
			for i=1, totalBricksAtStart do
				-- brick exists?
				if(bricks[i]) then
					bricks[i]:Update()
				end 
			end 
		end
		-- is level over?
		if(totalBricksBroken == totalBricks) then
			Events.allBricksBroken:Dispatch()
		end

	end
	----------------
	-- Events
	----------------
	function Bricks:allBricksBroken(event)
		-- cleanup bricks
		ClearBricks()
		local t = timer.performWithDelay( 1000, CreateAllBricksTimerCall)
		--CreateAllBricks()
		totalBricksBroken = 0		
		
		-- play happy sound for player to enjoy
		sound.play(sound.win)

		print(&quot;You Win!&quot;)
	end
	Events.allBricksBroken:AddObject(Bricks)
	CreateAllBricks(Levels.currentLevel)
	return Bricks

###Levels.lua

    
	local Events = require(&quot;Events&quot;)
	local Levels = {}
	local function MakeLevel(data)
		local level = {}
		level.xStart = data.xStart or 100
		level.yStart = data.yStart or 100
		level.xSpace = data.xSpace or 23
		level.ySpace = data.ySpace or 23
		level.align = data.align or &quot;center&quot;
		level.columns = data.columns or #data.bricks[1]
		level.bricks = data.bricks --&gt; required
		return level
	end
	Levels.test4 = MakeLevel
	{
		bricks =
		{
			{0,2,0,0,2,0,0,2,0},
			{0,0,2,0,2,0,2,0,0},
			{0,0,0,0,2,0,0,0,0},
			{1,1,2,1,1,1,2,1,1},
			{0,0,0,0,1,0,0,0,0},
			{0,0,0,0,1,0,0,0,0},
			{0,0,0,0,1,0,0,0,0},
		}
	}

	Levels.test5 = MakeLevel
	{
		bricks =
		{		
	        			{0,0,0,1,0,0,0,0},
					 	 {0,0,1,0,1,0,0,0},
					 	 {0,0,1,0,1,0,0,0},
					 	 {0,1,0,0,0,1,0,0},
					 	 {0,1,1,1,1,1,0,0},
					 	 {1,0,0,0,0,0,1,0},
					 	 {1,0,0,0,0,0,1,0},
					 	 {1,0,0,0,0,0,1,0},
					 	 {1,0,0,0,0,0,1,0}
		}
	}
	-- Levels.test6 = MakeLevel2
	-- {
	-- 	bricks =
	-- 	{
	----A 		  &quot;a&quot; = {{0,0,0,1,0,0,0,0},
	-- 				 	 {0,0,1,0,1,0,0,0},
	-- 				 	 {0,0,1,0,1,0,0,0},
	-- 				 	 {0,1,0,0,0,1,0,0},
	-- 				 	 {0,1,1,1,1,1,0,0},
	-- 				 	 {1,0,0,0,0,0,1,0},
	-- 				 	 {1,0,0,0,0,0,1,0},
	-- 				 	 {1,0,0,0,0,0,1,0},
	-- 				 	 {1,0,0,0,0,0,1,0}},
	----B
	-- 		      &quot;b&quot; = {{1,1,1,1,0,0,0},
	-- 				 	 {1,0,0,0,1,0,0},
	-- 				 	 {1,0,0,0,1,0,0},
	-- 				 	 {1,0,0,0,1,0,0},
	-- 				 	 {1,1,1,1,0,0,0},
	-- 				 	 {1,0,0,0,1,0,0},
	-- 				 	 {1,0,0,0,0,1,0},
	-- 				 	 {1,0,0,0,0,1,0},
	-- 				 	 {1,1,1,1,1,0,0}},
	--...........
	--.......
	--...
	-- --Z
	-- 		 	   &quot;z&quot;= {{1,1,1,1,1,1,1,0},
	-- 				 	 {0,0,0,0,0,1,0,0},
	-- 				 	 {0,0,0,0,1,0,0,0},
	-- 				 	 {0,0,0,0,1,0,0,0},
	-- 				 	 {0,0,0,1,0,0,0,0},
	-- 				 	 {0,0,1,0,0,0,0,0},
	-- 				 	 {0,0,1,0,0,0,0,0},
	-- 				 	 {0,1,0,0,0,0,0,0},
	-- 				 	 {1,1,1,1,1,1,1,0}}	
	-- 	}
	-- }
	-- stores all levels in ordered table so that one can be selected randomly by index
	Levels.levels = 
	{
		--Levels.test4,
		 Levels.test5
		-- Levels.test6,
	}
	function Levels:GetRandomLevel()
		return self.levels[math.random(#Levels.levels)]
	end
	Levels.notPlayedYet = {}
	Levels.currentLevel = Levels:GetRandomLevel()
	-- Events
	function Levels:allBricksBroken(event)
		self.currentLevel = Levels:GetRandomLevel()
	end
	Events.allBricksBroken:AddObject(Levels)
	return Levels

 
The work I&#39;ve done thus far (same as above) as an external download: http://www.mediafire.com/download/1t89ftkbznkn184/Breakout2.rar


  [1]: http://i.stack.imgur.com/Hl5Ga.png


Content Type	Original Author	Original Content on Stackoverflow
Question	Uskiver	View Question on Stackoverflow
Solution 1 - String	hugomg	View Answer on Stackoverflow
Solution 2 - String	Mud	View Answer on Stackoverflow

Check if a string isn't nil or empty in Lua

String Problem Overview

String Solutions

Solution 1 - String

Solution 2 - String

Trying to get PyCharm to work, keep getting "No Python interpreter selected"

find . -type f -exec chmod 644 {} ;

Attributions