Introduction
With RegEx Tester, you can fully develop and test your regular expression against a target text.
Its UI is designed to aid you in the RegEx development; especially the big and complex ones.
It uses and supports almost ALL of the features available in the .NET RegEx class.
About this article's writing, I have to tell you that English is not my native language and that I did my best in the redaction, grammar and spelling. You may and will find writing errors, so please tell me about them so that I can correct them.
Feature List
If you have an idea for a new feature, you could code it up and send it to me by email and I will add it here with the proper credits for your work. If you don't know how to properly code that idea, comment about it and other people (or me) can do it. Let's collaborate.
- Asynchronous execution enabling the user to abort the execution. Even if you make a Catastrophic Backtracking mess. [by Pablo Oses]
- Indented Input mode which strips \r \n \t \v and spaces before execution. This allows you to write those ugly, long and cryptic RegExs in an indented and spaced fashion. [by Pablo Oses]
- Replace mode which enables the use of
RegEx.Replace() function [by Pablo Oses] - Mono Compatible which makes it capable of running on Linux [by Pablo Oses]
- Test Text highlighting based on results selection [by Davide Mauri]
- F5 Hot Key to run the Test without changing the cursor position or selection. Get off of that Mouse ! [by Pablo Oses]
- Listing of the matches showing position, length and anonymous or named capture groups [by Davide Mauri and Pablo Oses]
- A button to "Clipboard Copy" the RegEx selecting "C# code snippet", "C# escaped
string", "HTML encoded" or "Plain text" modes [by Kurt Griffiths and Pablo Oses] - Adjust the size of each of the 3 sections of the window (RegEx, Text and Results). [by Pablo Oses]
- Ignore Case, MultiLine, SingleLine and Culture Invariant options [by Davide Mauri and Pablo Oses]
- Window resizing and maximizing capability [by Kurt Griffiths and Pablo Oses]
- Quick links to a RegEx Library and ILoveJackDaniels' CheatSheet [by Pablo Oses]
- Find function inside the Test Text [by Pablo Oses]
- Execution time measurements [by Pablo Oses]
What is Special About this Program?
As balazs_hideghety said in his comment, there are other popular, and great programs like RegEx buddy or Expresso that are extremely powerful and seem to be the last word on RegEx development and testing, but I still use this tool. Why? I needed a tool that helped me design HTML Extraction RegExs. For example (as of May 2009), if you evaluate this...
<td class="Frm_MsgSubject"><[^>]*?>(?<title>.*?)</a>.*?
<td class="Frm_MsgAuthor"><[^>]*?>(?<author>.*?)</a>.*?
<td class="Frm_MsgDate"[^>]*?>(?<date>.*?)&.*?
<td class="MsgBd BdSel ">.*?<td colspan="2">(?<body>[^<]*?)<"
... against the HTML source of this page, you would be parsing and extracting in only one operation all the comments inside this page with its corresponding title, body, date, user, etc. RegExs are really powerful when you are extracting data of real world websites. But the problem is that the RegExs needed are looooooong and extremely cryptic. You really start to need some spacing and indentation there to unofbuscate it and you need a big window with a lot of space and a test textbox able to handle big raw HTML documents so there's when this tool turns out to be really useful.
The same RegEx while I was developing it in RegExTester looked like this:
<td\sclass="Frm_MsgSubject"> <[^>]*? > (?<title>.*?) </a>
.*?
<td\sclass="Frm_MsgAuthor"> <[^>]*? > (?<author>.*?) </a>
.*?
<td\sclass="Frm_MsgDate" [^>]*? > (?<date>.*?) &
.*?
<td\sclass="MsgBd\sBdSel\s"> .*? <td\scolspan="2"> (?<body>[^<]*?) <
As you can see, I think that ugly RegEx development aid is the key feature of this program.
The Core of the Program: AsyncTest()
This is a simplified version of the function to make it more readable:
RegexOptions regexOptions = new RegexOptions();
if (cbIgnoreCase.Checked) regexOptions |= RegexOptions.IgnoreCase;
if (cbCultureInvariant.Checked) regexOptions |= RegexOptions.CultureInvariant;
if (cbMultiLine.Checked) regexOptions |= RegexOptions.Multiline;
if (cbSingleLine.Checked) regexOptions |= RegexOptions.Singleline;
if (cbIndentedInput.Checked) regexOptions |= RegexOptions.IgnorePatternWhitespace;
Regex regex = new Regex(txtRegEx.Text, regexOptions);
MatchCollection matchCollection = regex.Matches(rtbText.Text);
int matchesFound = matchCollection.Count;
if (cbReplaceMode.Checked)
rtbResults.Text = regex.Replace(rtbText.Text, txtRepEx.Text);
int[] groupNumbers = regex.GetGroupNumbers();
string[] groupNames = regex.GetGroupNames();
string groupName = null;
foreach (int groupNumber in groupNumbers)
{
if (groupNumber > 0)
{
groupName = "Group " + groupNumber;
if (groupNames[groupNumber] != groupNumber.ToString())
groupName += " (" + groupNames[groupNumber] + ")";
lvResult.Columns.Add(groupName, 100, HorizontalAlignment.Left);
}
}
foreach (Match match in matchCollection)
{
ListViewItem lvi = lvResult.Items.Add(match.ToString());
lvi.SubItems.Add(match.Index.ToString());
lvi.SubItems.Add(match.Length.ToString());
for (int c = 1; c < match.Groups.Count; c++)
{
lvi.SubItems.Add(match.Groups[c].Value);
}
rtbText.Select(match.Index, match.Length);
rtbText.SelectionColor = Color.Red;
}
The Asynchronous Execution Feature. Where the Fun Starts!
I first coded it using a BackgroundWorker but I had to throw it out because it seems that it's only useful when you want to abort a long loop that is IN your code... But it doesn't help you when you call an external function that takes too long to complete.
So I re-coded it from scratch using a more low level Thread managing that resulted in being more simple and clear than the previous technique once it was done.
private Thread worker;
private void MainForm_Load(object sender, System.EventArgs e)
{
Control.CheckForIllegalCrossThreadCalls = false;
}
private void btnTest_Click(object sender, System.EventArgs e)
{
if (btnTest.Text == STOPPED_MODE_BUTTON_TEXT)
{
StartTest();
}
else if (btnTest.Text == RUNNING_MODE_BUTTON_TEXT)
{
AbortTest();
}
}
private void StartTest()
{
worker = new Thread(AsyncTest);
worker.IsBackground = true;
worker.Start();
}
private void AbortTest()
{
if (worker.IsAlive) worker.Abort();
}
private void AsyncTest()
{
try
{
sbpStatus.Text = "Test running...";
sbpStatus.Text = "Test success.";
}
catch (ThreadAbortException)
{
sbpStatus.Text = "Test aborted by the user.";
}
catch (Exception e)
{
sbpStatus.Text = "Test aborted by an error.";
MessageBox.Show(e.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
}
finally
{
btnTest.Text = STOPPED_MODE_BUTTON_TEXT;
}
}
Program's History
This tool was originally written by Davide Mauri (2003). I used it A LOT at work and for personal projects. Thanks to the fact that it was open source, I started to add new features that I needed. One day the program was so different that I wanted to give all these enhancements to Davide so I contacted him by email and he gave me permission to re-release it and gave me the link to Kurt Griffith's version of the program (2006). I made a mix of his and my enhancements and polished the UI.
Recommended Links
Other Links
Article History
- 2011-05-21 - Article adapted to the new 3.2.0.0 version of the app
- 2009-05-03 - Article adapted to the new 3.1.0.0 version of the app
- 2008-03-08 - Moved histories to the bottom and updated links
- 2008-03-05 - Article adapted to the new 3.0.0.0 version of the app with async execution
- 2008-03-04 - Article completely rewritten to show and comment pieces of code used in the project
- 2008-03-02 - Initial article
Program History
- 2011-04-06 - 3.2.0.0 - by Pablo Osés
- New features
- Detection of multiple captures inside a capture group
- Minor changes
- Code janitoring
- Credits update in About Window
- 2010-02-25 - 3.1.1.0 - by Eric Lebetsamer
- 2009-05-03 - 3.1.0.0 - by Pablo Osés
- New features
RegEx.Replace() - Context menu icons
- C# code snippet copy
RichTextBoxes WordWrap - Execution time
- Mono compatible
- Bug fixes
- Label Typos
- New
SuspendLayout techniques and a lot of code re-engineering
- 2008-03-05 - 3.0.0.0 - by Pablo Osés
- New features
- Asynchronous execution
- Copy Feature enhanced
- Test
Textbox context menu - Find functions
- 2008-03-03 - 2.0.1.0 - by Pablo Osés
- New features
- Bug fixes
- Multiline behavior
- Performance issues
- Results list click event
- 2008-03-02 - 2.0.0.0 - by Pablo Osés
- New features
- Group names
- window maximize
- Hot Keys
- Indented Input
- Culture Invariant
- Resizeable Panels
- 2006-xx-xx - 1.0.0.3 - by Kurt Griffiths
- 2003-xx-xx - 1.0.0.3 - by Davide Mauri
