convert html to csv

There are many scripts using perl,php,python etc. that will do this for you
but the way you are about to see will make you smile of the simplicity of it .
instead of going over the file line by line and search inside , i am going to use
a tool that is going to do that for me . this tool is lynx , the console browser .
and here is how it works :

lynx -dump file_name.html

now, lets say our table looks like this :

1 2 3 4
5 6 7 8
9 10 11 12

to create a csv file from it , one would do something like this :
use ‘tr’ command to fold all spaces

tr -s " "

now , lets use sed to do the rest of the work for us .
this sed command will remove the first space/tab from the beginning of the lines

sed  's/^[ t]*//'

this sed command will place comma “,” as delimiter instead of space delimiter

sed  's/ /,/g'

So in the end we will end up with a simple one line command that creates a csv from html

lynx -dump file_name.html | tr -s " "|sed -e 's/^[ t]*//' -e 's/ /,/g' > file_name.csv

 
* note : the method shown here can work as long as there are no spaces in cell data

startup ubuntu in text mode

This common task turn out to be a pain in the … if you dont know how to do it .
Ubuntu unlike other Linux distributions moved from traditional sysvinit to Upstart .
i will not name all the differences but just one fact that setting a service to run in
requiered runlevel is not done by stop/start links in /etc/rcX.d anymore, but by init scripts .
Lets start . I use lxde as my desktop and lxdm as my desktop manager ,
i would like to have no Xserver on runlevel 3 ( runlevel 2 is Ubuntu default ) .
in order to do so i edit the file /etc/init/lxdm.conf and set the runlevels i wish lxdm
to start and stop . that is done by the commands
start on runlevel [2]
stop on runlevel [0136]

start on runlevel , was not found on the script so i added it .
now lxdm will start only on runlevel 2 and would stop on runlevel 0,1,3,6
Now boot into grub entry and append the runlevl to the kernel parameters
linux /boot/vmlinuz-2.6.38-8-generic root=/dev/sda1 ro quiet 3
to make it permanently you can create a new menu entry on /boot/grub/grub.cfg
You can read more on upstart at http://upstart.ubuntu.com/index.html

Eternal BASH History

Have you ever needed some command that you worked so hard for it
but it has being too long ago that it is already gone from Bash history ?
a simple solution is to use PROMPT_COMMAND Bash parameter .
how it works : PROMPT_COMMAND will execute the value as a command prior to issuing each primary prompt.
so if we set something like “history 1 >>~/.myhistory” , bash will write
the last history line to ~/.myhistory . nice ha
so in other words what can i do with that ?
well you can keep track of all commands , but there is a security issue
that needs to be taken , because this file saves all your history command ,
if you enter some passwords like running “mysql –password=blabla …”
it would be saved . so the first step would be to set permissions over the file
so only you can read it ( 0600 )

~$ chmod 600 ~/.myhistory

now lets put it all together by adding the line to your .bashrc

PROMPT_COMMAND='history 1 >> ~/.myhistory'

now when ever you login , the file will hold all your history ,
but now you see that every you press will write as the last command
as duplicate lines . the way i found to go around this is to simply remove duplicate
lines at login/logout . add this lines to ~/.bash_logout or ~/.bashrc

cat .myhistory |uniq >.myhistory2
mv -f .myhistory2 .myhistory 

Auto compleate service command

Have you ever wanted to have Tab to auto complete
any service and commands that comes with it ?
well i am going to show you how easy it is to do so .
all you need is to install a simple package that will do all the
hard work of typing for you .
the package name is bash-completion
once installed , you need to reload your profile and that’s it
just type service and tap will show you all services available
on your /etc/init.d . after you select the service you can hit tab once more
and it will display/complete the command associate with that service .
there is how ever another way of doing exactly that , by adding
words to bach tab completion . in this method all one needs to do is
run this command as root

~#complete -W "$(ls /etc/init.d/)" service 

the advantage of the package bash-completion is that it gives you some more
options as completion . for example if you use the cd command ,
it would auto complete only the directories listed under the current location .
without bash-completion the cd command + tab may show you files as well and
the best trick is that bash-completion also auto complete any commands related
to any service listed under /etc/init.d
choose what ever is best for you