Here is a fun trick which you can use, to simulate that a remote server is on one of your directories.
Create a folder call ~/m/example.com and in that folder create a file called .rvmrc with the following command
1 ssh awesomeuser@example.com -p 2302 -i ~/.ssh/awesomekey_rsa
2 #or whatever ssh command you use
Now whenever you run cd ~/m/example.com you will automagically be logged into your remote computer.
Obviously, this is a fun trick. All this can be done in a much nicer way using the ~/.ssh/config file.
Here are a few resources to make your ssh config more useful, allowing you to login to servers using a command like ssh myserver
I wonder what other stuff could be done using rvmrc.
View Comments »
Update: fixed the cron entry
I’ve read a very interesting article about “Why programmers work at night”. One of the points the author talks about is “how we get engrossed in twitter/hacker news/reddit”. I’ve felt the same. I think one of the reasons why we(programmers/developers) spend a lot of our time on twitter/hacker news/reddit is, because, we don’t have any idea of the time. Time just flies by. So, I created a small ruby script which nags you to get back to work :)
~/.scripts/nagger
1 #!/usr/bin/env ruby
2 require 'time'
3
4 exit if File.exists?("/tmp/stop-nagging")
5 #see what I did here ;)
6
7 #run the below command to find your display
8 #env | grep DISPLAY
9 ENV['DISPLAY'] = ':0.0'
10
11 last_line = `tail -2 ~/.gtimelog/timelog.txt`.lines.map{|x| x.chomp}.reject{|x| x.empty?}.reverse.first
12 minutes = ((Time.now - Time.parse(last_line[11, 5])) / 60).round
13 evil_monkey = File.expand_path File.join(File.dirname(__FILE__), 'evil-monkey.gif')
14
15 if minutes > 30
16 `notify-send -i '#{evil_monkey}' "It's been #{minutes} minutes since your last log"`
17 end
cron entry
1 0,5,10,15,20,25,30,35,40,45,50,55 * * * * /bin/bash -l -c '/home/minhajuddin/.scripts/nagger'
Hope it helps you get back to work too :). By the way, I use the awesome gtimelog app to log my time.
View Comments »
There are many instances where I had to replace some variable name in all my files. I use a small script to do this, Hope it helps you too.
1 #!/bin/bash
2 #~/.scripts/git-sub
3 #Author: Khaja Minhajuddin <minhajuddin@cosmicvent.com>
4 #script which does a global search and replace in the git repository
5 #it takes two arguments
6 #e.g. git sub OLD NEW
7
8 old=$1
9 new=$2
10
11 for file in $(git grep $old | cut -d':' -f 1 | uniq)
12 do
13 echo "replacing '$old' with '$new' in '$file'"
14 sed -i -e "s/$old/$new/g" $file
15 done
Just remember to add it to a directory which is in the $PATH. I have it in my ~/.scripts directory which is included in the $PATH. Name it git-sub and give it executable permissions using chmod +x ~/.scripts/git-sub. Now, you can just call git sub old_var new_var on terminal and it will do a global search and replace of all the files in the repository.
View Comments »
Functional programming allows you to write concise and elegant code. Mainstream languages like Ruby and C# support a lot of functional programming paradigms, and learning them makes you a better programmer. Below is a small example which demonstrates that:
1 #6 lines of ugly code
2 i = 0
3 tasks = list.tasks
4 while(i < tasks.length - 2)
5 tasks[i].priority.should >= tasks[i + 1].priority
6 i += 1
7 end
8
9
10 #3 lines of elegant functional code
11 list.tasks.each_cons(2).each do |t1, t2|
12 t1.priority.should >= t2.priority
13 end
I have a lot of git code repositories, and I usually gc (garbage collect) them manually by running the git gc command every now and then. Tasks like these are prime candidates for automating with cron. Below is a cron entry and the script which gcs my repositories. Hope you guys find it useful.
the script
1 #!/bin/bash
2 #author: Khaja Minhajuddin
3 #email: minhajuddin.k@gmail.com
4 #path /home/minhajuddin/.cron/reboot.sh
5 #description: script which is executed everytime computer starts
6
7 #git gc repos
8 REPO_DIRS=$(cat <<EOS
9 $HOME/repos
10 $HOME/repos/core
11 EOS
12 )
13
14 for repo_dir in $REPO_DIRS
15 do
16 echo "checking for git repos in $repo_dir"
17 for repo in $(ls $repo_dir)
18 do
19 cd $repo_dir/$repo
20 if [[ -d .git ]]
21 then
22 echo "garbage collecting $repo"
23 git gc
24 fi
25 done
26 done
the crontab entry
1 $ crontab -e
2 #add the line below into the editor and save it
3 @reboot $HOME/.cron/reboot.sh
Bonus tip: If you have a gitosis server, put the following script at ~git/.cron/reboot.sh and perform the above step for your git user.
the gitosis git user script
1 #!/bin/bash
2
3 for repo in $(ls ~/repositories)
4 do
5 cd ~/repositories/$repo
6 echo "garbage collecting $repo"
7 git gc
8 done
