Format your Perl scripts using Perl-Tidy and Notepad++

UPDATED on 8/15/2011 – The macro now automatically reloads the current file from disk, making this a 1 step re-tidy process.

I primarily use Notepad++ to write my Perl scripts because it is quick, offers code folding, syntax highlighting, and very useful keyboard shortcuts.

I’ve also begun using Perl::Tidy to “beautify” my Perl code. Perl::Tidy is available from CPAN, or available via Activestate’s Perl Package Manager (PPM).

To install via CPAN (if you use Strawberry Perl or Cygwin, this is the easiest method):

If you are not behind a proxy server (most people aren’t), just open a command prompt (or Cygwin shell) and enter:

perl -MCPAN -e shell

Once that has loaded, type:

install Perl::Tidy

Then wait a few moments for it to be installed. If you are behind a proxy server (such as at work), make sure that before you run “perl -MCPAN -e shell” that you set the environment variables in your command prompt. I make this simple by creating a batch file that I save as “proxy.bat” that contains the following:

REM Proxy.bat
set HTTP_proxy=http://myproxy.contosocom:8080
set FTP_proxy=http://myproxy.contosocom:8080

…and then I save that file (proxy.bat) somewhere in my PATH environment variable (such as c:\windows, or in my case I put c:\tools in my PATH environment variable). Then, I just run:

c:\tools\proxy.bat
perl -MCPAN -e shell

Once you have installed the Perl::Tidy module (either from PPM or CPAN), here is how you can integrate it into Notepad++ to re-format (or beautify) your current Perl script.

I am using Notepad++ v5.4.5, but you must ensure that you have the NppExec plugin installed with Notepad++. It is typically part of the standard installation.

Begin by opening Notepad++ and selecting the Plugins menu, NppExec submenu, and select Execute:

In the Execute dialog box, enter the following (note: change the path to perl.exe if your installation is different):

npp_save $(FULL_CURRENT_PATH)
perl -x -S perltidy -b "$(FULL_CURRENT_PATH)" -ole=win
npp_open $(FULL_CURRENT_PATH)

Then click Save…

NOTE, this command tells Perl-Tidy to create a backup of the current script (in the script’s directory) and clean up the code according to Perl-Tidy’s default formatting options. It will only create 1 backup file. If one already exists it is replaced. See here for other Perl-Tidy configuration options.

The second command tell Notepad++ to reload the file from disk once Perl::Tidy completes. This means changes are immediately updated in your active document.

Enter Perltidy as the script name when prompted.

Next select the Plugins menu, NppExec submenu, and select Advanced Options:

On the Advanced Options screen, first enter a menu item name, such as Run PerlTidy on current file. Then select PerlTidy on the Associated script drop-down box. Then be certain to click the Add/Modify button.

Now look at the top-left of the dialog box and click teh Place to the Macros submenu checkbox. Then click OK.

See the image below for a graphic that also shows the order of these operations:

You may receive a message from Notepad++ that you need to restart the program. Do that now.

Now you are ready to test it all out! Open up a Perl script that is in need of some formatting. If you aren’t sure if you have one, open up any Perl script, select all, and then press SHIFT+TAB several times to remove all indentation.

Now click on the Macro menu item and select Run PerlTidy on current file (or whatever you entered for Item Name from the previous step):

Now the last step is to reload the current script to see our change. Simply click on File and select Reload from Disk:

The above step is no longer necessary since I have updated this guide on 8/15/2011. The reason it isn’t necessary is because when creating our macro using NppExec, I specified the internal Notepad++ command, npp_open $(FULL_CURRENT_PATH), which reloads the file from disk once Perl::Tidy has executed.

npp_save $(FULL_CURRENT_PATH)
perl -x -S perltidy -b "$(FULL_CURRENT_PATH)" -ole=win
npp_open $(FULL_CURRENT_PATH)

Although this reloads the file from disk, when you click a different window on your desktop and then later click on Notepad++, you may receive a message stating that the file has been modified and it will ask if you want to reload it:

If you would like to suppress this message:

• Click the Settings menu
• Select Preferences
• Select the MISC. tab.
• Check Update Silently