I wrote the following in the `strings.xml` file:
    

    &lt;string name=&quot;game_settings_dragNDropMove_checkBox&quot;&gt;Move by Drag&amp;Drop&lt;/string&gt;

I got the following error:

    The reference to entity &quot;Drop&quot; must end with the &#39;;&#39; delimiter.

How can I write character &amp; in the strings.xml?

How to write character &amp; in android strings.xml

I would like a RegExp that will remove all special characters from a string. I am trying something like this but it doesn’t work in IE7, though it works in Firefox.

    var specialChars = &quot;!@#$^&amp;%*()+=-[]\/{}|:&lt;&gt;?,.&quot;;
    
    for (var i = 0; i &lt; specialChars.length; i++) {
      stringToReplace = stringToReplace.replace(new RegExp(&quot;\\&quot; + specialChars[i], &quot;gi&quot;), &quot;&quot;);
    }

A detailed description of the RegExp would be helpful as well.

Remove all special characters with RegExp

How are `\r` and `\n` different? I think it has something to do with Unix vs. Windows vs. Mac, but I&#39;m not sure exactly how they&#39;re different, and which to search for/match in regexes.

What is the difference between \r and \n?

Is there any comprehensive list of characters that need to be escaped in Bash? Can it be checked just with `sed`?

In particular, I was checking whether `%` needs to be escaped or not. I tried

    echo &quot;h%h&quot; | sed &#39;s/%/i/g&#39;

and worked fine, without escaping `%`. Does it mean `%` does not need to be escaped? Was this a good way to check the necessity?

And more general: are they the same characters to escape in `shell` and `bash`?

Which characters need to be escaped when using Bash?

What was the original historical use of the vertical tab character (`\v` in the C language, ASCII 11)?

Did it ever have a key on a keyboard? How did someone generate it?

Is there any language or system still in use today where the vertical tab character does something interesting and useful?


What is a vertical tab?

What does 

    echo $?

mean in shell programming?

Meaning of $? (dollar question mark) in shell scripts

I want to remove all special characters except space from a string using JavaScript.

For example,
`abc&#39;s test#s`
should output as
`abcs tests`.

Remove all special characters except space from a string using JavaScript

I have a TextView and I want to add a bullet symbol in my text through XML. Is it possible?

How do I add a bullet symbol in TextView?

Where can I find a list of allowed characters in filenames, depending on the operating system?
(e.g. on Linux, the character `:` is allowed in filenames, but not on Windows)

Allowed characters in filename

This is what I have now:

    $(&quot;input&quot;).bind(&quot;keydown&quot;,function(e){
        var value = this.value + String.fromCharCode(e.keyCode);
    }

If the `e.keyCode` may not be an ASCII character (&lt;kbd&gt;Alt&lt;/kbd&gt;, &lt;kbd&gt;backspace&lt;/kbd&gt;, &lt;kbd&gt;del&lt;/kbd&gt;, &lt;kbd&gt;arrows&lt;/kbd&gt;, etc.)...
I would now need to `trim` these values from `value` somehow (preferably programmatically - not with lookup tables).

I&#39;m using jQuery.

I must use the `keydown` event. `keyPress` doesn&#39;t activate for certain keys I need to capture (&lt;kbd&gt;Esc&lt;/kbd&gt;, &lt;kbd&gt;del&lt;/kbd&gt;, &lt;kbd&gt;backspace&lt;/kbd&gt;, etc.).

I cannot use `setTimeout` to get the input&#39;s value. `setTimeout(function(){},0)` is too slow.

Get Character value from KeyCode in JavaScript... then trim

The problem is that, as you know, there are thousands of characters [in the Unicode chart][1] and I want to convert all the similar characters to the letters which are in English alphabet.

For instance here are a few conversions:

    ҥ-&gt;H
    Ѷ-&gt;V
    Ȳ-&gt;Y
    Ǭ-&gt;O
    Ƈ-&gt;C
    tђє Ŧค๓เℓy --&gt; the Family
    ...

and I saw that there are more than 20 versions of letter A/a. and I don&#39;t know how to classify them. They look like needles in the haystack. 



The complete list of unicode chars is at [http://www.ssec.wisc.edu/~tomw/java/unicode.html][2]  or [http://unicode.org/charts/charindex.html][3] . Just try scrolling down and see the variations of letters. 

How can I convert all these with Java? Please help me :(

  [1]: http://www.ssec.wisc.edu/~tomw/java/unicode.html
  [2]: http://www.ssec.wisc.edu/~tomw/java/unicode.html
  [3]: http://unicode.org/charts/charindex.html

Converting Symbols, Accent Letters to English Alphabet

How do I block special characters from being typed into an input field with jquery?

How do I block or restrict special characters from input fields with jquery?

What is the complete list of all special characters for a SQL (I&#39;m interested in SQL Server but other&#39;s would be good too) LIKE clause?

E.g.

    SELECT Name FROM Person WHERE Name LIKE &#39;%Jon%&#39;

**&lt;a href=&quot;http://msdn.microsoft.com/en-us/library/ms179859.aspx&quot;&gt;SQL Server&lt;/a&gt;:**

 1. %
 2. _
 3. [specifier] E.g. [a-z]
 4. [^specifier]
 5. ESCAPE clause E.g. %30!%%&#39; ESCAPE &#39;!&#39; will evaluate 30% as true
 6. &#39; characters need to be escaped with &#39; E.g. they&#39;re becomes they&#39;&#39;re

[**MySQL:**][1]

 1. `%` - Any string of zero or more characters.
 2. `_` - Any single character
 3. ESCAPE clause E.g. %30!%%&#39; ESCAPE &#39;!&#39; will evaluate 30% as true

[**Oracle:**][2]

 1. `%` - Any string of zero or more characters.
 2. `_` - Any single character
 3. ESCAPE clause E.g. %30!%%&#39; ESCAPE &#39;!&#39; will evaluate 30% as true

**Sybase**

 1. %
 2. _
 3. [specifier] E.g. [a-z]
 4. [^specifier]

**[Progress:][4]**

 1. `%` - Any string of zero or more characters.
 2. `_` - Any single character

 [Reference Guide here][3] [PDF]

**[PostgreSQL:][5]**

 1. `%` - Any string of zero or more characters.
 2. `_` - Any single character
 3. ESCAPE clause E.g. %30!%%&#39; ESCAPE &#39;!&#39; will evaluate 30% as true


**[ANSI SQL92:][6]**

 1. %
 2. _
 3. An ESCAPE character *only if specified*.

PostgreSQL also has the `SIMILAR TO` operator which adds the following:

  3. `[specifier]`
  4. `[^specifier]`
  5. `|` - either of two alternatives
  6. `*` - repetition of the previous item zero or more times.
  7. `+` - repetition of the previous item one or more times.
  8. `()` - group items together

The idea is to make this a community Wiki that can become a &quot;One stop shop&quot; for this.


  [1]: http://dev.mysql.com/doc/refman/5.0/en/string-comparison-functions.html#operator_like
  [2]: http://dev.mysql.com/doc/refman/5.0/en/string-comparison-functions.html#operator_like
  [3]: http://www.progress.com/progress/products/documentation/docs/sql92/e92/e92.pdf
  [4]: http://www.progress.com
  [5]: http://www.postgresql.org/docs/7.4/interactive/functions-matching.html
  [6]: http://www.contrib.andrew.cmu.edu/~shadow/sql/sql1992.txt

List of special characters for SQL LIKE clause

We are designing a URL system that will specify application sections as words separated by slashes.  Specifically, this is in GWT, so the relevant parts of the URL will be in the hash (which will be interpreted by a controller layer on the client-side):

    http://site/gwturl#section1/section2

Some sections may need additional attributes, which we&#39;d like to specify with a `:`, so that the section parts of the URL are unambiguous.  The code would split first on `/`, then on `:`, like this:

    http://site/gwturl#user:45/comments

Of course, we are doing this for url-friendliness, so we&#39;d like to make sure that none of these characters which will hold special meaning will be url-encoded by browsers, or any other system, and end up with a url like this:

    http://site/gwturl#user%3A45/comments &lt;--- BAD

Is using the colon in this way &lt;b&gt;safe&lt;/b&gt; (by which I mean won&#39;t be automatically encoded) for browsers, bookmarking systems, even Javascript or Java code?

Is a colon `:` safe for friendly-URL use?

I have a log file (application.log) which might contain the following string of normal &amp; special characters on multiple lines:

    *^%Q&amp;$*&amp;^@$&amp;*!^@$*&amp;^&amp;^*&amp;^&amp;

I want to search for the line number(s) which contains this special character string.

&lt;!-- language: sh --&gt;

    grep &#39;*^%Q&amp;$*&amp;^@$&amp;*!^@$*&amp;^&amp;^*&amp;^&amp;&#39; application.log

The above command doesn&#39;t return any results.

What would be the correct syntax to get the line numbers?

grep for special characters in Unix

I&#39;m generating a CSV file (delimited by commas rather than tabs). My users will most likely open the CSV file in Excel by double clicking it. My data may contain commas and speech marks, so I&#39;m escaping those as follows.

    Reference, Title, Description
    1, &quot;My little title&quot;, &quot;My description, which may contain &quot;&quot;speech marks&quot;&quot; and commas.&quot;
    2, &quot;My other little title&quot;, &quot;My other description, which may also contain &quot;&quot;speech marks&quot;&quot; and commas.&quot;

As far as I know that&#39;s always been the way to do it. Here&#39;s my boggle: when I open this file in Excel 2010 my escaping is not respected. Speech marks appear on the sheet, and the comma causes new columns.



How should I escape commas and speech marks in CSV files so they work in Excel?

since the beginning of my programmation, I used some special character like &quot;&lt;-&quot;, &quot;&quot;&lt;&lt;&quot; im my string.xml in Eclipse while developping for Android.

All worked fine for one year, but today, i just wanted to make some minor changes and began to edit my xml files.

I get now compilation error on these characters because eclipse believe it&#39;s part of the xml blocks.


Any idea on how I could add this symbol &quot;&lt;&quot; in my xml files?

Thank a lot.

writing some characters like &#39;&lt;&#39; in an xml file

So I&#39;m finally reading through [K&amp;R](https://en.wikipedia.org/wiki/The_C_Programming_Language), and I learned something within the first few pages, that there is a backspace escape character, `\b`.

So I go to test it out, and there is some very odd behavior:

    #include &lt;stdio.h&gt;
    
    main ()
    {
        printf(&quot;hello worl\b\bd\n&quot;);
    }

The output is

    hello wodl

Can anyone explain this?

The &quot;backspace&quot; escape character &#39;\b&#39;: unexpected behavior?

I&#39;m editing a network protocol frame stored a file in Unix (`\n` newlines). I need to insert the carriage return character (`U+000D` aka `\r`). When I try to paste it from the clipboard (`&quot;+p`) or type it using &lt;kbd&gt;Ctrl&lt;/kbd&gt;+&lt;kbd&gt;Shift&lt;/kbd&gt;+&lt;kbd&gt;u&lt;/kbd&gt;-`000d`, the linefeed is inserted (`U+000A`).

What is the right way to do it?


Insert the carriage return character in vim

How would one enter special characters into a `Label` in C# (Windows Forms)? 

If you try to write a &quot;&amp;&quot; into a label you&#39;ll get a sort of underscore instead..

So what&#39;s the C# equivalent of &quot;&amp;&quot;? (&quot;\&amp;&quot; obviously doesn&#39;t work).


Enter &quot;&amp;&quot; symbol into a text Label in Windows Forms?

I&#39;m trying to find the Unicode symbol to make a button display the Unicode pause symbol. I was able to find that the Unicode play symbol is `&amp;#9658` but I&#39;m looking for the equivalent of the Unicode pause symbol.

HTML for the Pause symbol in audio and video control

I have a text file containing unwanted null characters (ASCII NUL, `\0`). When I try to view it in `vi` I see `^@` symbols, interleaved in normal text. How can I:

1. Identify which lines in the file contain null characters? I have tried grepping for `\0` and `\x0`, but this did not work.

2. Remove the null characters? Running `strings` on the file cleaned it up, but I&#39;m just wondering if this is the best way?

Identifying and removing null characters in UNIX

I have a list where I want to add tick symbol before list text. Is there any CSS that can help me to apply this way?

    ✓ this is my text
    ✓ this is my text
    ✓ this is my text
    ✓ this is my text
    ✓ this is my text
    ✓ this is my text

Note: I want this in this type of HTML code

&lt;!-- begin snippet: js hide: false --&gt;

&lt;!-- language: lang-html --&gt;

    &lt;ul&gt;
      &lt;li&gt;this is my text&lt;/li&gt;
      &lt;li&gt;this is my text&lt;/li&gt;
      &lt;li&gt;this is my text&lt;/li&gt;
      &lt;li&gt;this is my text&lt;/li&gt;
      &lt;li&gt;this is my text&lt;/li&gt;
    &lt;/ul&gt;

&lt;!-- end snippet --&gt;




How to use tick / checkmark symbol (✓) instead of bullets in unordered list?

Which characters are allowed in GET parameters without encoding or escaping them? I mean something like this:

http://www.example.org/page.php?name=XYZ

What can you have there instead of XYZ? I think only the following characters:

 - a-z (A-Z)
 - 0-9
 - -
 - _

Is this the full list or are there additional characters allowed?

I hope you can help me. Thanks in advance!

Characters allowed in GET parameter

How do you check if a String contains a special character like: 

    [,],{,},{,),*,|,:,&gt;,


Check if a String contains a special character

The following code works on the command line

    mysql --user=&#39;myusername&#39; --password=&#39;mypassword&#39; --database=&#39;mydatabase&#39; --execute=&#39;DROP DATABASE myusername; 
    CREATE DATABASE mydatabase;&#39;

However, it doesn&#39;t work on bash file on execution

    #!/bin/bash
    user=myusername
    password=mypassword
    database=mydatabase

    mysql --user=&#39;$user&#39; --password=&#39;$password&#39; --database=&#39;$database&#39; --execute=&#39;DROP DATABASE $user; CREATE DATABASE $database;&#39;

I receive the following error:
&gt;ERROR 1045 (28000): Access denied for user &#39;$user&#39;@&#39;localhost&#39; (using password: YES)

How to make the bash file run as the command line?

How to run MySQL command on bash?

In this Java source code I have this line:

    if ((modifiers &amp; ~KeyEvent.SHIFT_MASK) != 0) ....

What does the tilde `~` mean?



Java: What does ~ mean

What characters are you allowed to use in a subdomain?

Example: for `someSub.example.com` the `someSub` portion. 

I know you can use letters, numbers, and hyphens, but what about other characters? Can `_` (underscore) be used? 

What are the allowed characters in a subdomain?

I found this code in Python for removing emojis but it is not working. Can you help with other codes or fix to this? 

I have observed all my emjois start with `\xf` but when I try to search for `str.startswith(&quot;\xf&quot;)` I get invalid character error.

    emoji_pattern = r&#39;/[x{1F601}-x{1F64F}]/u&#39;
    re.sub(emoji_pattern, &#39;&#39;, word)

Here&#39;s the error:

    Traceback (most recent call last):
      File &quot;test.py&quot;, line 52, in &lt;module&gt;
        re.sub(emoji_pattern,&#39;&#39;,word)
      File &quot;/usr/lib/python2.7/re.py&quot;, line 151, in sub
        return _compile(pattern, flags).sub(repl, string, count)
      File &quot;/usr/lib/python2.7/re.py&quot;, line 244, in _compile
        raise error, v # invalid expression
    sre_constants.error: bad character range

Each of the items in a list can be a word `[&#39;This&#39;, &#39;dog&#39;, &#39;\xf0\x9f\x98\x82&#39;, &#39;https://t.co/5N86jYipOI&#39;]`

UPDATE:
I used this other code:

    emoji_pattern=re.compile(ur&quot; &quot; &quot; [\U0001F600-\U0001F64F] # emoticons \
                                     |\
                                     [\U0001F300-\U0001F5FF] # symbols &amp; pictographs\
                                     |\
                                     [\U0001F680-\U0001F6FF] # transport &amp; map symbols\
                                     |\
                                     [\U0001F1E0-\U0001F1FF] # flags (iOS)\
                              &quot; &quot; &quot;, re.VERBOSE)
    
    emoji_pattern.sub(&#39;&#39;, word)
But this still doesn&#39;t remove the emojis and shows them! Any clue why is that?
[![enter image description here][1]][1]


  [1]: http://i.stack.imgur.com/8xXfy.png

removing emojis from a string in Python

Do you know how to look for special characters with google...? 

I&#39;m looking at bash code and there&#39;s the ## operator. I would like to know what It does but I wasn&#39;t able to figure out a way to protect the character (I&#39;m not sure it&#39;s even possible).

This is particularly annoying when you&#39;re looking for some code patterns, some characters are always ignored.



Looking for special characters in Google

For example, in a Windows folder, if we create some files and name them 1.html, 2.txt, 3.txt, photo.jpg, zen.png the order will be as is. But if we create another file with the name _file.doc it will be placed at the top. (considering we sort by name in descending order)

likewise, what would be the character that would be considered as the first, such that if i use that character, it would place the file on top of the hierarchy?

What is the first character in the sort order used by Windows Explorer?

I have an issue with some content that we are downloading from the web for a screen scraping tool that I am building.

in the code below, the string returned from the web client download string method returns some odd characters for the source download for a few (not all) web sites.

I have recently added http headers as below. Previously the same code was called without the headers to the same effect. I have not tried variations on the &#39;Accept-Charset&#39; header, I don&#39;t know much about text encoding other than the basics.

The characters, or character sequences that I refer to are:

&quot;**&#239;&#187;&#191;**&quot; 

and

 &quot;**&#194;**&quot;

These characters are not seen when you use &quot;view source&quot; in a web browser. What could be causing this and how can I rectify the problem?

    string urlData = String.Empty;
    WebClient wc = new WebClient();
    
    // Add headers to impersonate a web browser. Some web sites 
    // will not respond correctly without these headers
    wc.Headers.Add(&quot;User-Agent&quot;, &quot;Mozilla/5.0 (Windows; U; Windows NT 6.1; en-GB; rv:1.9.2.12) Gecko/20101026 Firefox/3.6.12&quot;);
    wc.Headers.Add(&quot;Accept&quot;, &quot;*/*&quot;);
    wc.Headers.Add(&quot;Accept-Language&quot;, &quot;en-gb,en;q=0.5&quot;);
    wc.Headers.Add(&quot;Accept-Charset&quot;, &quot;ISO-8859-1,utf-8;q=0.7,*;q=0.7&quot;);
                
    urlData = wc.DownloadString(uri);

WebClient.DownloadString() returns string with peculiar characters

What&#39;s the difference between `iconv()` and `mb_convert_encoding()` in PHP?  Does one perform better, faster, etc. ( eg. with specific encodings )? In what situations would one be preferred over the other?

Here&#39;s what I think I know already:

**iconv()**

1. included with most installs of PHP.
2. when characters that can&#39;t be mapped to the new character set are found, you can specify if they are converted to a &#39;similar&#39; character, or ignored.

**mb_convert_encoding()**

1. usually requires installing the php-mbstring extension.
2. is able to handle `HTML-ENTITIES`, converting to and from web hex codes.

Are there other differences?

What is the difference between iconv() and mb_convert_encoding() in PHP?

Is there a bigger version of `&amp;bull;`?

&amp;bull; Right now it is this big 

- I want it this big without using font sizes or `&lt;li&gt;`



Bigger version of &amp;bull;

After [proudly coloring my liststyle bullet without any image url or span tags][1], via:

    ul{ list-style: none; padding:0;  margin:0;  }
    li{ padding-left: 1em; text-indent: -1em;    }
    li:before { content: &quot;■&quot;; padding-right:7px; }

Although these stylesheets work perfectly down to the rounded borders and other css3 stuff, and  although the recipient of the email (for instance, Eudora OSE 1) renders all css styles correctly, just like in a browser, there is one problem: the bullets like `•` or `■` become converted into `&amp;#adabacadabra;`

Appearing finally like so in emails: 

![enter image description here][2]

How do I proceed from here?

  [1]: https://stackoverflow.com/questions/5306640/how-to-define-the-color-of-bullets-in-ul-li-lists-via-css
  [2]: http://i.stack.imgur.com/t3okD.png

li:before{ content: &quot;■&quot;; } How to Encode this Special Character as a Bullit in an Email Stationery?

How can space and tab be represented in an XML tag?

Are there any special characters that can represent them?

Represent space and tab in XML tag?

**What is the best way to check the text area value for line breaks and then calculate the number of occurrences, if any?**

I have a text area on a form on my webpage. I am using JavaScript to grab the value of the text area and then checking its length.

### Example

    enteredText = textareaVariableName.val();
    characterCount = enteredText.length; // One line break entered returns 1

If a user enters a line break in the text area my calculation above gives the line break a length of 1. However I need to give line breaks a length of 2. Therefore I need to check for line breaks and the number of occurrences and then add this onto the total length.

### Example of what I want to achieve

    enteredText = textareaVariableName.val();
    characterCount = enteredText.length + numberOfLineBreaks;

----------

My solution before asking this question was the following:

    enteredText = textareaVariableName.val();
    enteredTextEncoded = escape(enteredText);
    linebreaks = enteredTextEncoded.match(/%0A/g);
    (linebreaks != null) ? numberOfLineBreaks = linebreaks.length : numberOfLineBreaks = 0;

I could see that encoding the text and checking for `%0A` was a bit long-winded, so I was after some better solutions. Thank you for all the suggestions.


How to detect line breaks in a text area input?

I am pulling in some information from a database that contains dimensions with both &#39; and &quot; to denote feet and inches.  Those characters being in my string cause me problems later and I need to replace all of the single and double quotes.  I can successfully get rid of one or the other by doing:

    this.Vals.replace(/\&#39;/g, &quot;&quot;)   To get rid of single quotes
 or

    this.Vals.replace(/\&quot;/g, &quot;&quot;)   To get rid of double quotes

How do I get rid of both of these in the same string.  I&#39;ve tried just doing

    this.Vals.replace(/\&quot;&#39;/g, &quot;&quot;)
 and

    this.Vals.replace(/\&quot;\&#39;/g, &quot;&quot;)

But then neither get replaced.

Replace Both Double and Single Quotes in Javascript String

I have the following string...

    NSString *googleSearchString = @&quot;http://www.google.com/search?q=lyrics+%22T&#230;nder+P&#229;+Dig%22+%22Jakob+Sveistrup%22&quot;;

Notice that it has some accented characters. When I try to turn that into a url the returned url is null...

    [NSURL URLWithString:googleSearchString];

So normally the url works except when there are accented non-english characters in the string. Any help on how to handle that?

NSURL URLWithString: is null with non-english accented characters

I am trying to validate a string, that should contain letters numbers and special characters `&amp;-._` only. For that I tried with a regular expression.

    var pattern = /[a-zA-Z0-9&amp;_\.-]/
    var qry = &#39;abc&amp;*&#39;;
    if(qry.match(pattern)) {
        alert(&#39;valid&#39;);
    }
    else{
        alert(&#39;invalid&#39;);
    }

While using the above code, the string `abc&amp;*` is valid. But my requirement is to show this invalid. ie Whenever a character other than a letter, a number or special characters `&amp;-._` comes, the string should evaluate as invalid. How can I do that with a regex? 

Matching special characters and letters in regex

I was doing the challenges from [pythonchallenge][1] writing code in ruby, [specifically this one][2]. It contains a really long string in page source with special characters. I was trying to find a way to delete them/check for the alphabetical chars. 

I tried using scan method, but I think I might not use it properly. I also tried `delete!` like that:

        a = &quot;PAGE SOURCE CODE PASTED HERE&quot;
        a.delete! &quot;!&quot;, &quot;@&quot;  #and so on with special chars, does not work(?) 
        a
How can I do that? 

Thanks


  [1]: http://www.pythonchallenge.com
  [2]: http://www.pythonchallenge.com/pc/def/ocr.html

Deleting all special characters from a string - ruby

My company runs MySQL in NO_BACKSLASH_ESCAPES mode. How can I escape a literal `%` or `_` in a LIKE query in this mode? The standard way is `\%`, but that doesn&#39;t work in this mode.

Example: a column has the following values: `5% off`, `50% off`. The following query works in standard mode but not in NO_BACKSLASH_ESCAPES mode:

    SELECT * FROM mytable
    WHERE mycol LIKE &#39;5\% off&#39;

All Special Characters Solutions on Gang of Coders

Total of 42 Special Characters Solutions