scheme page 3 - Dave's Blog

Backup Notes

2007 Jul 13, 8:30I bought an external backup drive a few weekends ago. I've previously setup a Subversion repository so I decided to move everything into the repository and then back it up. So in went the contents of all of my %USERPROFILE% and ~ directories with a bit of sorting and pruning. Not too much though given its much easier to dump in everything and search for what I want then to take the time to examine and grade each file. What follows are the notes I took while setting this up. It takes me a bit of time to look up the help on each command so I figure I'll write it all down here for the benefit of myself and potentially others...

Setting Up the Backup Drive For Linux
I first changed the filesystem on the drive to ext3. I plugged it into my USB2.0 port and ran fdisk:

sudo fdisk /dev/sda

Useful commands I used to do this follow mostly in order:

m

help

p

print current partitions

d

delete current partition

n

create new partition (I used the defaults)

w

write changes and exit

Then I formatted for ext3.

sudo mkfs.ext3 /dev/sda1

I made it easy to mount:

sudo vim /etc/fstab
# added line to end:
/dev/sda1 /media/backup ext3 rw,user,noauto 0 0

I setup the directory structure on the disk

mount /media/backup
sudo mkdir /media/backup/users
sudo mkdir /media/backup/users/dave
sudo chown dave:dave /media/backup/users/dave

After all that its easy to make a copy of the Subversion repository:

mount /media/backup
cp -Rv /home/dave/svn /media/backup/users/dave/
umount /media/backup

Next on the agenda is to add a cron job to do this regularly.

Subversion Command Reference
On a machine that has local access to the Subversion repository you can check out a specific subdirectory as follows using the file scheme:

svn co file:///home/dave/svn/trunk/web/dave%40deletethis.net/public_html

Note also that although one of my directories is named 'dave@deletethis.net' Subversion requires the '@' to be percent-encoded.
Other useful subversion commands:

svn help

help

svn list file:///home/dave/svn/

list all files in root dir of svn depot

svn list -R file:///home/dave/svn/

list all files in svn depot

svn list -R file:///home/dave/svn/ | grep \/$

list all directories

svn status

List status of all files in the working copy directory as in - modified, not in repository, etc

svn update

Brings the working copy up to date wrt the repository

svn commit

Commit changes from the working copy to the repository

svn add / move / delete

Perform the specified action -- occurs immediately

Setting up Windows Client for Auto Auth into SVN
When using an SVN client on Windows via svn+ssh its useful to have the Windows automatically generate connections to the SVN server. I use putty on my Windows machines so I read the directions on using public keys with putty.

putty.exe dave@deletethis.net
cd .ssh
vim authorized_keys # leave the putty window open for now
puttygen.exe
Click the 'generate' button
Move the mouse around until finished
Copy text in 'Public key for pasting into OpenSSH authorized_keys file:' to putty window & save & close putty window
Enter Key passphrase & Comment in puttygen
Save the private key somewhere private
pageant.exe
'Add Key' the private key just saved.

Checking out using Tortoise SVN
On one of my Windows machines I've already installed Tortoise SVN. Checking out from my SVN repository was really easy. I just right clicked in Explorer in a directory and selected "SVN Checkout...". Then in the following dialog I entered the svn URI:

svn+ssh://dave@deletethis.net/home/dave/svn/trunk/web/dave%40deletethis.net/public_html/

Note again that the '@' that is part of the directory name is percent-encoded as '%40' while the '@' in the userinfo is not.

Windows Command Line Check Out
On my media center I didn't want to install Tortoise SVN so rather I used the command line tool. I setup pageant like before the only difficulty was getting the SVN command line tool to use putty. With the default configuration you can use the SVN_SSH environment variable to point at a compliant SSH command line tool. The trick is that its interpreted as a backslash escaped string. So I set mine thusly:

set SVN_SSH=C:\\users\\dave\\bin\\putty\\plink.exe

The escaping solved the vague error I received about not being able to create the tunnel.backup technical personal windows svn linux subversion

XPointer Framework - IE7 XML Source View Upgrade Part 3

2007 May 17, 5:16Previously I created some resource tools and then I used them to overwrite msxml3's XML source view. In this update I've added support for the XPointer Framework.

This time around I've started to add support for the XPointer Framework to my XML source view and I've added installation instructions. The framework consists of a series of pointer segments each of which has a scheme name followed by data in parenthesis. For example 'scheme1(data1)scheme2(data2)scheme3(data3)'. A pointer segment resolves to a portion of the XML document based on the data and the scheme name. The whole pointer resolves to the first segment that successfully resolves. That is, from the example, if scheme1 resolves to nothing and scheme2 resolves to something then that's used and scheme3 is ignored. In addition to the framework I've added support for the xmlns scheme which binds namespace prefixes to a namespace URI and the element scheme which is a simple way to resolve to particular elements in an XML. I also have limited support for the xpointer scheme the content of which is resolved as an XPath with some extra functions (which I don't support -- hence the limited). I've also thrown in schemes for the two SelectionLanguage values supported by msxml3.

Next time I might try to support the xpointer functions that aren't in xpath using msxml script. But I think I'm losing steam on this project... we'll see.resource technical xml xpointer res xpath xslt

New XSLT - IE7 XML Source View Upgrade Part 2

2007 May 11, 8:55Last time, I had written some resource tools to allow me to view and modify Windows module resources in my ultimate and noble quest to implement the XML content-type fragment in IE7. Using the resource tools I found that MSXML3.DLL isn't signed and that I can replace the XSLT embedded resource with my own, which is great news and means I could continue in my endevour. In the following I discuss how I came up with this replacement for IE7's XML source view.

At first I thought I could just modify the existing XSLT but it turns out that it isn't exactly an XSLT, rather its an IE5 XSL. I tried using the XSL to XSLT converter linked to on MSDN, however the resulting document still requires manual modification. But I didn't want to muck about in their weird language and I figured I could write my own XSLT faster than I could figure out how theirs worked.

I began work on the new XSLT and found it relatively easy to produce. First I got indenting working with all the XML nodes represented appropriately and different CSS classes attached to them to make it easy to do syntax highlighting. Next I added in some javascript to allow for closing and opening of elements. At this point my XSLT had the same features as the original XSL.

Next was the XML mimetype fragment which uses XPointer, a framework around various different schemes for naming parts of an XML document. I focused on the XPointer scheme which is an extended version of XPath. So I named my first task as getting XPaths working. Thankfully javascript running in the HTML document produced by running my XSLT on an XML document has access to the original XML document object via the document.XMLDocument property. From this this I can execute XPaths, however there's no builtin way to map from the XML nodes selected by the XPath to the HTML elements that I produced to represent them. So I created a recursive javascript function and XSLT named-template that both produce the same unique strings based on an XML node's position in the document. For instance 'a3-e2-e' is the name produced for the 3rd attribute of the second element of the root element of the XML document. When producing the HTML for an XML node, I add an 'id' attribute to the HTML with the unique string of the XML node. Then in javascript when I execute an XPath I can discover the unique string of each node in the selected set and map each of them to their corresponding positions in the HTML.

With the hard part out of the way I changed the onload to get the fragment of the URI of the current document, interpret it as an XPath and highlight and navigate to the selected nodes. I also added an interactive floating bar from which you can enter your own XPaths and do the same. On a related note, I found that when accessing XML files via the file URI scheme the fragment is stripped off and not available to the javascript.

The next steps are of course to actually implement XPointer framework parsing as well as the limited number of schemes that the XPointer framework specifies.xml xpointer msxml res xpath xslt resource ie7 technical browser ie xsl

Resource Tools - IE7 XML Source View Upgrade Part 1

2007 May 9, 4:15I read about text/xml URI fragment resolution a few months ago. I was interested to find another kind of fragment reference other than the text/html URI fragment but of course I didn't find an implementation in IE, Firefox, or Opera. I decided to see how much work would be required to implement this in IE.

In IE and Firefox when you open an XML file that doesn't have an XML stylesheet the XML source is rendered with syntax highlighting. In IE I also noticed that the gold bar appears when you open an XML file off of your local machine. To me this suggested that the XML source was being rendered as HTML which I assumed was produced by running an XSLT on the source XML file. If so, I figured I could modify the XSLT to implement text/xml URI fragments. I ran FileMon to see if iexplore.exe loaded an XSLT file when opening an XML file. Only the XML file and MSXML3.DLL were opened and no XSLTs were loaded as files. My next hope for modifying the XSLT was if it existed as a resource in MSXML3.DLL. I did a findstr on the DLL for SCRIPT and found an XSLT so I decided to check for resources in MSXML3.DLL. Unfortunately my previous resource viewer didn't work correctly so I decided to write my own.

I created resource tools to view and modify resources in Windows modules. The viewer outputs HTML with links to the individual resources of a module using the res URI scheme that's built into IE. The modifier is a simple command line tool that replaces or adds one resource at a time to a module.

Using these tools I found that the XSLT was stored as a resource in MSXML3.DLL. I'll talk more about the existing XSLT and the one I replaced it with next time.resource technical xml msxml res xslt xsl