imposing some of my programming style on a whole source tree of files (muahahaha!)

I inherited a project at my current job that had only been worked on by one person before, over a long period of time. I've been refactoring it for quite a while, now, and one thing that I've done a lot of during this is reformat into a style that I'm used to/more comfortable with. I've done this largely with the help of various sets of regular expressions, using either search and replace in TextPad (my text editor of choice) or a combination of find/grep/sed/etc.

Here's one that I did fairly recently, which, while not incredibly useful or complicated, did what I needed it to do. I also had fun figuring out the right expressions, and enforcing my programming style on hundreds of files with one commandline. :)

for f in `find . -name '*.jsp'`; do echo $f; sed -e 's/^\([ \t]\+\)\(.*[^ \t]\+.*\)[ \t]*{$/\1\2\n\1{/g' -e 's/^\([ \t]*\)}[ \t]*\([^ \t]\+.*\)$/\1\}\n\1\2/g' $f >$f.2; diff $f $f.2; mv $f.2 $f; chmod 755 $f; done

I created this in two parts, originally in textpad, then decided I wanted to put them together and run them on all of the JSPs in the source tree. Here are the two parts, as I documented them originally, which should make it easier to understand the final command above:

----
move {'s from ends of code lines to blank lines,
for example:
    try {
would change to:
    try
    {

search for:
^([ \t]*)(.*[^ \t]+.*)\{\n
replace with:
\1\2\n\1{\n

sed -e 's/^\([ \t]\+\)\(.*[^ \t]\+.*\)[ \t]*{$/\1\2\n\1{/g' FileName.jsp
----
move }'s from beginnings of code lines to blank lines,
for example:
    } catch (Exception e)
would change to:
    }
    catch (Exception e)

search for:
^([ \t]*)\}[ \t]*([^ \t]+.*)\n
replace with:
\1\}\n\1\2\n

sed -e 's/^\([ \t]*\)}[ \t]*\([^ \t]\+.*\)$/\1\}\n\1\2/g' FileName.jsp
----

-spugbrap

remote access to a firewalled machine with ssh port forwarding

At some point last year, I needed to be able to remotely control a computer at work that could not be accessed from the outside world due to a firewall. I already knew the power of ssh port forwarding, and figured there was some way to accomplish what I wanted to do using ssh.

Sure enough, I was able to put together the following two commands, which allowed me to do what I needed to do, with the help of my computer at home (whose firewall I could actually open a port on). I only did it once, just to see if it could really be done, but I did not want to risk getting in trouble for making a hole in the firewall. It was a fun exercise, though, and I wanted to share it with anyone who cares to listen.

The following represent things to modify in the commandlines below, to suit your own needs:

HOME_IP = the ip address of my machine at home
HOME_USER = my username on my machine at home
RESTRICTED_HOSTNAME = the hostname of the machine I'm trying to open up
RESTRICTED_USER = my username on the machine I'm trying to open up

First, I executed this command from the machine I wanted to open up to the outside world:
ssh -g -R 8022:localhost:22 HOME_USER@HOME_IP

This forwards my local port 22 (on the restricted machine) to my home machine's port 8022
-g tells it to allow remote hosts to connect to locally forwarded ports


Next, I executed this command in that ssh session to my home machine that I created with the first command:
ssh -p 8022 -N -f -g -L 15900:RESTRICTED_HOSTNAME:5900 RESTRICTED_USER@localhost

This forwards the VNC port (5900) on the machine I'm trying to open up to port 15900 on my home machine.
-g tells it to allow remote hosts to connect to locally forwarded ports
-N says I just want to make this connection for port forwarding, not to actually execute a command
-f says to put ssh into the background after establishing the connection


Now, from any machine with an internet connection and a VNC client, I can open a VNC connection to HOME_IP:15900, and I will be remotely controlling the restricted machine.

Note that this only requires me to have ports 22 and 15900 open on my firewall at home.%

Time to start using this blog for what it's made for!

I've been continuing to keep a text file with my favorite scripts, regexes, commandlines, utilities, etc., but have totally slacked as far as posting that stuff in this blog. I had a feeling that would happen, which I said in the intial blog description post, but I want to go ahead and start putting some of that info in here now.

I was just going to post that entire text file, but I realized I need to sanitize it a bit to remove proprietary information. Plus, the file is pretty bare, and could really use at least a LITTLE documentation, particularly because some of the regular expressions are hard to follow without some idea of their purpose.

So, I will start posting bits and pieces from that file, with some description, hopefully on a regular basis. You can expect the first post later tonight or tomorrow morning. Again, these are little things that were useful to me in some way, which I wanted to save for future reference. I hope some of it can be of use to other people.

Also, if anyone knows other blogs with similar purposes (utils, scripts, code snippets, useful commands/combinations of commands, etc.), please share the URL in a comment in this blog.

-dave (spugbrap)