{"id":577,"date":"2014-10-07T00:01:00","date_gmt":"2014-10-07T00:01:00","guid":{"rendered":"https:\/\/blogs.technet.microsoft.com\/heyscriptingguy\/2014\/10\/07\/converting-words-to-ascii-numbers-and-back-with-powershell\/"},"modified":"2014-10-07T00:01:00","modified_gmt":"2014-10-07T00:01:00","slug":"converting-words-to-ascii-numbers-and-back-with-powershell","status":"publish","type":"post","link":"https:\/\/devblogs.microsoft.com\/scripting\/converting-words-to-ascii-numbers-and-back-with-powershell\/","title":{"rendered":"Converting Words to ASCII Numbers and Back with PowerShell"},"content":{"rendered":"

Summary<\/b>: Use Windows PowerShell to convert words to ASCII numbers and back again.<\/span><\/p>\n

Microsoft Scripting Guy, Ed Wilson, is here. Today, I am sipping a nice cup of Earl Grey tea with just a little jasmine in it. Along with a cinnamon stick, it is a nice mellow cup. I am checking my email sent to scripter@microsoft.com<\/a> on my Surface Pro 3, and playing around with Windows PowerShell. I thought it would be fun to open the project I started yesterday when I created a couple of hash tables.<\/p>\n

Note <\/b> Today’s post continues yesterday's post: Automatically Create Hash Tables and Reverse Value with PowerShell<\/a>.<\/i> You really need to read yesterday’s post first, or today's post will not make any sense. (This does not mean it will make sense, but to have a fighting chance, you really need to read yesterday’s post.)<\/p>\n

Put the hash tables to work<\/h2>\n

So I have two hash tables. The first hash table contains ASCII values and associated letters:<\/p>\n

\"Image<\/a><\/p>\n

Notice that I do not use an OrderedDictionary<\/b> object because I could not do the look up like I want to if I use it. So the output of the hash table is a bit jumbled. That is fine, because I am not displaying it, only searching it.<\/p>\n

The second hash table (the $ltrFirst<\/b> hash table) is shown here:<\/p>\n

\"Image<\/a><\/p>\n

The first thing to do is to encode a string into an array of numbers. To do this, I store my string in a variable, and I call the ToCharArray<\/b> method. I then pipe the characters to the Foreach-Object<\/b> cmdlet (%<\/b> is an alias), and I use the letters from the word to perform a look up in the $ltrFirst<\/b> hash table. The result outputs an array of numbers equal to the ASCII values of the word:<\/p>\n

PS C:\\> $w = "dog"                                                               <\/p>\n

$w.ToCharArray() | % {$ltrFirst["$_"]}<\/p>\n

100<\/p>\n

111<\/p>\n

103<\/p>\n

  Note<\/b>  Because I am looking up against strings, I need to use quotation marks around the $_<\/b>, which contains
  each letter from the word stored in $w<\/b>.<\/p>\n

To be useful, I need to store the array of numbers in a variable, as shown here:<\/p>\n

$n = $w.ToCharArray() | % {$ltrFirst["$_"]}   <\/p>\n

Decode<\/h2>\n

I want to be able to decode the numbers and convert them back into a word. To do this, I use the $ASCIIFirst<\/b> hash table so that I can look up letters by their numeric value. I pipe the numeric array stored in the $n<\/b> variable to the Foreach-Object<\/b> cmdlet (%<\/b> is the alias), and I use the number to look up by key in the $ASCIIFirst<\/b> hash table. This time, I do not need any quotation marks because I am comparing numbers to numbers. Here is the example of doing this:<\/p>\n

PS C:\\> $n | % {$ASCIIFirst[$_]} <\/p>\n

d<\/p>\n

o<\/p>\n

g<\/p>\n

So I know that my technique works. Now I store results in a variable instead of simply displaying them to the screen. This is shown here:<\/p>\n

$c = $n | % {$ASCIIFirst[$_]}    <\/p>\n

If I look at $c<\/b>, I will still see an array of letters, not an actual word. To put the pieces back together, I use the –Join<\/b> operator:<\/p>\n

PS C:\\> $c -join '' <\/p>\n

dog<\/p>\n

Of course if I need to, I can store the results in another variable that I can use for other purposes. The complete code is shown here:<\/p>\n

#AsciiEncodeDecodeWords.ps1<\/p>\n

# ed wilson<\/p>\n

# hsg-10-6,7-14<\/p>\n

# —————————————————————————–<\/p>\n

$ASCIIFirst=$ltrFirst=$null<\/p>\n

$ASCIIFirst = @{}<\/p>\n

$ltrFirst = @{}<\/p>\n

97..122 |<\/p>\n

  Foreach-Object {<\/p>\n

    $ASCIIFirst.Add($_,([char]$_).ToString())}<\/p>\n

 <\/p>\n

foreach($k in $ASCIIFirst.Keys)<\/p>\n

    {$ltrFirst.add($ASCIIFirst[$k],$k)}<\/p>\n

 <\/p>\n

$w = "dog"                                                               <\/p>\n

$w.ToCharArray() | % {$ltrFirst["$_"]}                                   <\/p>\n

$n = $w.ToCharArray() | % {$ltrFirst["$_"]}                              <\/p>\n

$n | % {$ASCIIFirst[$_]}                                                 <\/p>\n

$c = $n | % {$ASCIIFirst[$_]}                                            <\/p>\n

$c -join ''            <\/p>\n

That is all there is to using Windows PowerShell to use hash tables to convert words to ASCII characters and back. Join me tomorrow when I will talk about more cool Windows PowerShell stuff.<\/p>\n

I invite you to follow me on Twitter<\/a> and Facebook<\/a>. If you have any questions, send email to me at scripter@microsoft.com<\/a>, or post your questions on the Official Scripting Guys Forum<\/a>. See you tomorrow. Until then, peace.<\/p>\n

Ed Wilson, Microsoft Scripting Guy<\/b> <\/span><\/p>\n","protected":false},"excerpt":{"rendered":"

Summary: Use Windows PowerShell to convert words to ASCII numbers and back again. Microsoft Scripting Guy, Ed Wilson, is here. Today, I am sipping a nice cup of Earl Grey tea with just a little jasmine in it. Along with a cinnamon stick, it is a nice mellow cup. I am checking my email sent […]<\/p>\n","protected":false},"author":596,"featured_media":87096,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[1],"tags":[537,3,4,45],"class_list":["post-577","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-scripting","tag-hash-tables","tag-scripting-guy","tag-scripting-techniques","tag-windows-powershell"],"acf":[],"blog_post_summary":"

Summary: Use Windows PowerShell to convert words to ASCII numbers and back again. Microsoft Scripting Guy, Ed Wilson, is here. Today, I am sipping a nice cup of Earl Grey tea with just a little jasmine in it. Along with a cinnamon stick, it is a nice mellow cup. I am checking my email sent […]<\/p>\n","_links":{"self":[{"href":"https:\/\/devblogs.microsoft.com\/scripting\/wp-json\/wp\/v2\/posts\/577","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/devblogs.microsoft.com\/scripting\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/devblogs.microsoft.com\/scripting\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/scripting\/wp-json\/wp\/v2\/users\/596"}],"replies":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/scripting\/wp-json\/wp\/v2\/comments?post=577"}],"version-history":[{"count":0,"href":"https:\/\/devblogs.microsoft.com\/scripting\/wp-json\/wp\/v2\/posts\/577\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/scripting\/wp-json\/wp\/v2\/media\/87096"}],"wp:attachment":[{"href":"https:\/\/devblogs.microsoft.com\/scripting\/wp-json\/wp\/v2\/media?parent=577"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/scripting\/wp-json\/wp\/v2\/categories?post=577"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/devblogs.microsoft.com\/scripting\/wp-json\/wp\/v2\/tags?post=577"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}