Numerical Recipes Cambridge

How to Install the Plugin for Adobe Reader

Important Note

We no longer support the FileOpen interface to Numerical Recipes. However, many users still report success in using it. If you want to try, you need to install the FileOpen free plugin on your device. Currently, we recommend doing this according to the instructions at the FileOpen Plugin web page.

Old Instructions

Instructions for Microsoft Windows
Instructions for Mac OS X
Instructions for Linux
Frequently Asked Questions About the Plugin

Microsoft Windows

Quick Windows Instructions

Get the Fileopen® plugin here. Move it to your Adobe Reader® plug_ins directory. Restart Adobe Reader. That is all!

Very Detailed Windows Instructions

1. Download the file FileOpen.api by clicking here. You should get a choice "Save to Disk". Save the file to somewhere that you will be able to find it, for example your desktop. If you do not get a "Save to Disk" (or similar choice) then right-click on this link and choose "Save Target as..." or "Save Link as..." Depending on your Windows settings, you will see it named either FileOpen.api or else just FileOpen.

(You will now locate your Adobe Reader® (or Acrobat® Reader) plugins directory, named "plug_ins", as follows:)

2. Click the "Start" button. Choose "Run". In the text box, enter "explorer" and click "OK". An explorer window will appear. In its left explorer panel click on "My Computer", then "C:", then "Program Files", then "Adobe". If you have a nonstandard installation, you might have to find the "Adobe" folder on another disk, or in another place, but this is rare.

3. After clicking in the left explorer panel on the "Adobe" folder, you may see several folders in the right explorer panel, with names like "Acrobat 7.0", "Acrobat Reader 7.0", "Reader 8.0", etc. You want to open (double-click) the one that your browser is actually using to open PDF documents. It will generally be the one with the highest version number. If you have both an "Acrobat X.X" and a "Reader X.X" with the same version number X.X, you will usually want the "Acrobat X.X" folder. However, there is no harm in performing the following steps on more than one version.

4. In the (e.g.) "Acrobat 7.0" or "Reader 8,0" folder that you just opened, there will be a folder named "Acrobat" or "Reader". Double click to open it.

5. You should now see the folder "plug_ins" in the right explorer panel. Double click to open it. You should see various Adobe plugins, for example "Accessibility", "AcroForm", "ADBC", etc. (None of these are necessary for this install, however.)

(You will now actually install the plugin, simply by moving it to the correct place:)

6. Drag the FileOpen.api file from your desktop (or wherever you put it) into the right explorer panel with the other plugins. Once you see it there, you may close the explorer window.

7. Close all open instances of Acrobat or Reader. Note that these sometimes can be running in the background. If you know how to close these by right-clicking on an empty part of the taskbar, choosing Task Manger, clicking on its "Processes" tab, right-clicking on the Acrobat.exe process, and choosing "End Process", then do so. Otherwise, you might need to logout and login again, or even reboot your machine (very rare).

8. Test your installation by clicking here. After a few seconds' delay, you should see a document that confirms that your FileOpen plugin is working properly. If you don't, then see Troubleshooting, below.

Automatic Installation

FileOpen Systems has an automatic installation option that you can access as a web applet here, or as a download here. We do not recommend this method, because it does not always work properly on some Windows configurations. However, we have never seen it do any harm, so you might want to give it a try. Then, test your installation by clicking here.

Apple Macintosh OS X

Mac Instructions for Adobe Acrobat or Reader versions 9

The instructions below for Reader version 8 will also work for Reader version 9, but you will probably have to do the manual installation that starts at step 5. See here for more detailed instructions.

Mac Instructions for Adobe Acrobat or Reader versions 7 and 8

1. Verify that you can read this PDF file using Adobe Acrobat or Reader. If your browser is Safari, you can set it to use Adobe Reader 8 as a plugin (see this Adobe technical note if you have trouble with this). If your browser is Firefox or your Acrobat version is 7, you'll probably have to save PDF files and then separately open them with Acrobat or Adobe Reader. Other PDF readers won't work, because they cannot use the FileOpen plugin. Adobe Reader 8 can be downloaded for free here.

2. Download the installation dmg file "FileOpenMacInstall.dmg" here. Double click to its icon to mount it. Now double click on the new icon of the mounted disk to open it. You should see (among other items), a "box" icon for FileOpenInstaller.

3. Unlike the Windows version, we have had good experience with the the automatic installer. Be sure to exit (not just iconify) Safari or any other brower before installing. Double-click on FileOpenInstaller. It should confirm a successful install.

4. Test your installation by downloading and viewing this document with Acrobat or Adobe Reader. After a few seconds' delay, you should see a confirmation that your FileOpen plugin is working properly. You can now skip the rest of these instructions.

5. If you don't get a confirmation (for example, error messages like "Missing component not found" or "Checking for updates"), then you must do a manual install. Quit Adobe reader if it is still running. Now, open a new Finder window by clicking on the desktop and then choosing File/New Finder Window in the Finder menu bar.

6. On the left, click Applications, then locate the Adobe Reader folder. Double click on it, to open it. Inside you will find the Adobe Reader application. Don't double click on it! Rather, right-click on it once and choose Get Info. (Or, you can left-click on it once and then keyboard Command-I -- it's the same thing.)

7. Towards the bottom of the info window, expand the Plug-ins section and click the Add button. Now, in the window, navigate to the previously mounted FileOpenMacInstall image drive and choose the correct item from these choices: For Adobe Acrobat/Reader 7, choose the file named "FileOpen7.acroplugin". For Adobe Acrobat/Reader 8, choose the folder "FileOpen8.acroplugin". NEVER choose the file named "FileOpen.acroplugin".

8. After you click the Choose button, you should see the FileOpen plugin added to the list of plugins in the Info box. Close all open windows and do the test in step 4.

9. See Troubleshooting, below, especially about firewall issues.

Mac Instructions for Adobe Reader 6 and earlier

1. We only support Adobe Reader 7 and later. However, there is still a chance for you: Do steps 1 and 2 in the instructions above.

2. Open the Readme file, which is provided by FileOpen Systems (not us!). Perhaps it will help you. This is where you will use the file "FileOpen.acroplugin" which we avoided above. Good luck.


Important: We are still waiting for a fix from FileOpen that will let the plug-in work with Acrobat/Reader 9 under Linux. Right now we have no workaround, only apologies. For the latest update, see this thread.

If you are using an older Linux distribution (e.g., Suse earlier than 10.2 or Fedora Core earlier than 6), AND you are using Acrobat Reader 8 (not 7), then see this thread before proceeding.

Note: Some previous versions of the FileOpen Linux plugin didn't work correctly (e.g., "Error #2115"). Be sure to install the new version, downloaded via the links on this page below.

Quick Linux Instructions

Verify that you are using Adobe Acrobat or Reader to view PDF files. Get the plugin here for Adobe Reader 7, or here for Adobe Reader 8. Move it to your Adobe Reader plug_ins directory and make it executable. Create a directory named ".fileopen" in your home directory and make sure it is writeable by you. That is all!

Very Detailed Linux Instructions

1. Check whether your browser is set up to use Acrobat Reader or Adobe Reader for viewing PDF documents by viewing this document. (This step has nothing to do with the plugin.) Firefox and Opera can be configured to use Adobe Reader within the browser; Konqueror can be configured to automatically launch the Adobe Reader externally. PDF readers other than Adobe won't work, because they cannot use the FileOpen plugin. If you need to install Adobe Reader, go to this Adobe web page.

2. Download the plugin from here for Adobe Reader 7, or here for Adobe Reader 8, and save it to disk in a convenient place such as your desktop or /tmp/FileOpen.api . It doesn't matter what it is named, as long as the name ends in .api

(You will now locate your Adobe Reader (or Acrobat Reader) plugins directory, named "plug_ins", as follows:)

3. The most likely location for Reader 7 is "/usr/X11R6/lib/Acrobat7/Reader/intellinux/plug_ins". The most likely location for Reader 8 is "/opt/Adobe/Reader8/Reader/intellinux/plug_ins". If the first part of this path is not right, you can usually figure out what it should be by doing the command (at a shell prompt) "whereis acroread" or else "which acroread". If your Adobe or Acrobat Reader is not in X11R6/lib or /opt/Adobe, it is probably somewhere in a directory named "acroread" (or "Acrobat7" or similar) that contains directories Browser, bin, Resource, and Reader. So if whereis returns something like blahblah/bin/acroread, with some nontrivial blahblah, it is likely that plug_ins is somewhere below blahblah/Reader. Go down through the blahblah directories to find it. If whereis returns something like /usr/bin/acroread, on the other hand, you will probably find that this is a symbolic link to the actual location. Go to /usr/bin and do "ls -l" to find where it links to.

(You will now actually install the plugin, simply by moving it to the correct place:)

4. When you have found the plug_ins directory, copy the FileOpen.api file into it. If it has some other name, that is OK, as long as it ends in ".api". You will likely have to become root for this step, using the "su" command. You can then do the copy by a "cp" command at a shell prompt. Alternatively, you can drag the file in your GUI (again becoming root).

5. Now you must make the FileOpen.api file executable. At a shell prompt in the plug_ins directory, the command is "chmod 755 FileOpen.api".

(You will now create a writeable subdirectory ".fileopen" in your home directory, as follows:)

6. Get out of being root by a CTRL-D or exit command (this is IMPORTANT). As yourself, go to your home directory by the command "cd ~". Now, as yourself, create a writeable directory ".fileopen" by the command "mkdir .fileopen". Do the command "ls -lad .fileopen" and verify that .fileopen is owned by you (not root) and is writeable (has permissions beginning with "drwx").

7. Close all instances of Adobe Reader. If you have any open browsers, including this one, you may need to close it also, since Adobe Reader may be running in the background. Then reopen your browser to this page.

8. Test your installation by clicking here. After a few seconds' delay, you should see a document that confirms that your FileOpen plugin is working properly. If you don't, then see Troubleshooting, below, especially items 2 and 3.


1. First we must check whether you have a working installation of Acrobat Reader or Adobe Reader. (This has nothing to do with the plugin.) Click here. You should see a comforting document. If you don't see it, then you don't have a working Adobe Reader installation. Click here to go to the Adobe website and download the latest free version. (Linux and Mac users note: If you see the document in a PDF reader other than Adobe, you will not be able to proceed, since the FileOpen plugin is specific to Adobe. Click on the link above to download the free Adobe Reader for Linux or Mac.)

2. Next we must check whether your Adobe Reader has found the FileOpen plugin. To do this, we need to open Reader in its own window, i.e., not in a browser. In Windows, click the "Start" button, then "Programs". Look for "Adobe Acrobat Reader" or a similar choice. Open that program. In Linux, type "acroread" at a shell prompt. In Mac OSX open a finder window, choose Applications, Adobe Reader (folder), then launch Adobe Reader. [An alternative on all systems is to right-click on this link. Choose "Save Target as..." or "Save Link as...", and save it to your desktop. Now, on your desktop, double click on it. An instance of Acrobat or Reader should open.] In the menu bar, click "Help" (Windows or Linux) or "Adobe Reader" (Mac). A choice should be "About Third-Party Plug-Ins", and clicking on it should show "FileOpen WebPublisher" as installed. If not, try rebooting your machine. If it is still not there, then you may have moved the FileOpen plugin (FileOpen.api file) into the wrong plug_ins directory. Try repeating the Very Detailed Instructions above to locate the correct directory.

3. If you do find the "About Third-Party Plug-Ins" and "FileOpen WebPublisher" items in Adobe Reader, but this link still doesn't work (i.e., after 20 seconds has a blank page, an error message like "Unable to connect to server", or nothing at all), then we must determine whether we have an SSL problem: Try this link, which uses port 80, not SSL port 443. If it works, then your plugin is correctly installed and the problem is with its using SSL. Check if your firewall is blocking outgoing connections from the plugin to remote port 443, but allowing them to remote port 80.

4. If neither of the test links in step 3 worked, then we have no direct confirmation that the plugin is working. Nevertheless, the overwhelming majority of problems at this stage are firewall problems, not plugin problems. In using the FileOpen plugin, Adobe Acrobat/Reader downloads information from an ordinary https (SSL, remote port 443) web page. You must set your firewall to allow this outgoing connection. Regrettably, we cannot tell you how to do this, because there are too many kinds of internal and external firewalls in use, but it is generally a very straightforward setting to make.

5. If you are still having trouble, please post a description of the problem on the Numerical Recipes Forum under "Plugin Problems", or look there to see if someone else has already solved your problem.