Erics Tech Blog » Tips

Using Vi Mode Everywhere

eric — Tue, 15 Mar 2011 07:00:07 +0000

Not literally everywhere, but more places than usual. I have been looking for this solution for a long time and finally found it. Anyone who has ever worked around me knows that I do basically everything in Vi.

Not only do I use it to edit files, but I use it as an IDE for development (even on my Mac instead of Textmate). So the natural extension is for me to use it in the command prompt as well. So in my .bashrc file, I have the line:

set -o vi

This allows me to navigate the bash console with the usual vim suspects: h, j, k, l. In addition to that, I also get some fun ones like word movement w and the dw that goes along with it.

But the big winner for me is now I am able to use the vim environment and movement keys inside the irb (Ruby), Mongo, MySQL consoles (still not Redis though). To do that, just add the following lines to the following files:

$ echo "bind -v" >> ~/.editrc
$ echo "set editing-mode vi" >> ~/.inputrc

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Counting Frequencies of Frequencies

eric — Mon, 16 Aug 2010 12:30:13 +0000

Lots of people forget about the usefulness of the core utilities (the tools available in Bash). I am even pretty guilty of it at times with such quick and easy things like Perl, Ruby, or Python that allow you to process items from the command line. However, they load up an entire interpreter. It is usually better to use the coreutils.

I’ll give you the specific example I had to deal with, but this can be extrapolated out and I’m sure reused for other purposes. I have lists of email addresses of who has received emails that were sent over the past 7 days. I do this with a find command since the address files are created nightly. They are laid out with 1 email address (and some other meta data) per line. You’ll notice the awk in the find command; that’s just to extract the email address from the line to make things easier to work with.

The overall goal here is find out how many times people were emailed over the past 7 days. Another way of saying it is, how many people received 1,2,3,4, etc mailings over the past week. This is an exercise in aggregation.

First, here is everything in its entirety and then I will proceed to go through it all piece by piece.

$ find /nfs/mailings/lists/ -maxdepth 3 -ctime -7 -name "master_list.txt" \
-exec awk '{print $2}' '{}' >> /tmp/emails.txt \; && cat /tmp/emails.txt | \
awk '{ for (i=1;i< =NF;i++) count[$i]++ } END { for (i in count) print count[i], i }' $* |\
awk '{print $1}' | awk '{ for (i=1;i<=NF;i++) count[$i]++ } \
END { for (i in count) print count[i], i }' $* | awk '{print $2,$1}' | \
sort -n && rm -rf /tmp/emails.txt
1 93278
2 21415
3 16924
4 3064131
5 548421
6 102

A quick breakdown goes as follows.

1) Find all mailing list master files (-name) that aren’t archived (-maxdepth) that were created in the last 7 days (-ctime) and print their id (exec awk) to a tmp file. Everything here needs to be concatenated so as not to clobber the emails added by the previous day.

find /nfs/mailings/lists/ -maxdepth 3 -ctime -7 -name "master_list.txt"\
-exec awk '{print $2}' '{}' >> /tmp/emails.txt \;

2) The next piece word frequency counts the emails and prints them to STDOUT in a manner. This is to say that the first column is a count of how many times the second column has received an email over the past 7 days. Now we know how many emails each individual has received and we need to aggregate again.

cat /tmp/emails.txt | awk '{ for (i=1;i< =NF;i++) count[$i]++ } \
END { for (i in count) print count[i], i }' $*

3) Because I am using pipes, instead of printing the previous step to STDOUT, I only print the first column (count) and then count the frequency of that.

awk '{print $1} | awk '{ for (i=1;i< =NF;i++) count[$i]++ } \
END { for (i in count) print count[i], i }' $*

4) Then I swap the columns so I get . This is much more logical and is the way we generally read tables.

awk '{print $2,$1}'

5) Finally I sort that result numerically ascending and remove the temp file so I don't cat things to it again.

sort -n && rm -rf /tmp/emails.txt

6) We get our output in an easy to read format (Note: I added the headers).

Freq Total
1 93278
2 21415
3 16924
4 3064131
5 548421
6 102

Random Tech Notes And Buzz Updates

eric — Mon, 28 Jun 2010 12:00:00 +0000

Since Google Buzz is Twitterish in the sense that you can post a quick note, but different in the sense that (amongst other things), it can be longer than 140 characters. So in that vein, I’m starting to try to make a habit of a quick post (a couple per week) of things I do to make my life easier. This goes both for SysAdmins and for Programmers.

I’ll be adding things for everything from Vim and Bash, to MySQL, Perl, Ruby, Python, and any other language or app that I happen to be using shortcuts in. If you have another idea or a better way to do something, I’d love to hear it. So add a comment or hit me up on Twitter (@elubow). I’ve already got a few up there so check them out.

And for the record, I am not trying to mimic or one up something like commandlinefu.com. Just providing things that work well in my world.

The Google Buzz account is here.

Peertester Community Testing

eric — Tue, 16 Mar 2010 11:00:02 +0000

I am all about community and people participating in a community. Its the way social media succeeds. But there are non-social media communities out there too (yes I know that’s shocking). I was recently asked to participate in a beta testing for Peer Tester. I think this is an absolutely fantastic idea. Developers helping other developers test their apps. Hats off to the guys and gals over at Engine Yard for designing and putting this application together. Other than the fact that I got tired of looking at that olive green color after years in the military, this site is an great tool for developers.

So now you’re probably asking what exactly it is. Well, you create an account and then create tests for your web application. The tester will then follow your instructions, clicking on what you tell them to do or reading what you tell them to read. Then they are asked questions (multiple choice, short answer, or whatever suits the situation) while they are going through the testing. You can then view their feedback and modify (or not modify) your application accordingly.

For people like me who absolutely suck at flow and visual aesthetics, this is great to see if others think your product elicits the expected reaction. You can even specify the number of people you want to use as a sample size for testing. But just like with any good community site, you need to participate in order to have the site excel. You gain points and get badges for participation and bug finding.

Remember, the site is still in beta (and I can only hope that it will change the site color before it gets out of beta, but that’s me) so there may be some bugs. I encourage everyone to take a look. A little extra application testing never hurt anyone.

Git Command Aliases

eric — Mon, 28 Dec 2009 12:45:10 +0000

This is kind of a tip of the day, but I just think its cool so I am sharing it with everyone. And being a recent convert to Git and the fact that I have to use Subversion at my place of work, I find myself constantly doing things like this out of habit.

$ git st && git ci

Well now I can do that (although it may not be a good idea) with git alias:

elubow@beacon (master) supportskydivers$ git config --global alias.st status
elubow@beacon (master) supportskydivers$ git config --global alias.ci commit
elubow@beacon (master) supportskydivers$ git st && git ci
# On branch master
nothing to commit (working directory clean)

Now st and ci are git aliases for status and commit respectively.