Create a file with random numbers

Sometimes we need to create a file that contains several random numbers. Using bash programming we can do that very quickly. Example,

mycomputer ~% for i in {1..1000}; do echo $RANDOM; done >> nums.txt

This command executes a for loop 1000 times, prints the random variable $RANDOM and redirect the output to the file nums.txt

Print a random integer in the bash console

If you need a random positive integer, you can print the variable $RANDOM. For example:

mycomputer ~% echo $RANDOM
120865

Replace a string in several files

[CONTEXT]
You need to replace a string in several files

[HOW]
There several options to do this, 

• sed:         Syntax:    $ sed -i "s/old_string/new_string/g" files
                  Example  $ sed -i "s/foo/bar/g" *.txt 
• perl:       Syntax:    $ perl -i -p -e "s/old_string/new_string/g;" files  

                        

[SOURCE]
sed man page 
http://www.cyberciti.biz/faq/unix-linux-replace-string-words-in-many-files/ 

Managing your latex bib files in linux II

[CONTEXT]
You want a program to manage your Latex bibliography file.
[HOW]
Jabref  is a really good program to organize and modify your bib files in Latex using a very friendly GUI. Also this program can generate  automatically the key for the bib entries and you can include the link to your pdf files.

To install it, we can use the package in Debian's repository
# aptitude install jabref

[SOURCE]
http://jabref.sourceforge.net/

Synchronize a folder outside the default Dropbox's directory

[CONTEXT]
You want to synchronize a folder with Dropbox, without move that folder to
the default  Dropbox's directory
[HOW]
Create a symbolic link from the folder that you want to synchronize to the Dropbox directory, for example

$ ln -s /path/to/folder/to/sync ~/Dropbox

The permissions of the files or folders should be (at least) owner:r/w, group r/w, and others: r
-rw-rw-r-- 

[SOURCE]
http://www.dropboxwiki.com/tips-and-tricks/sync-other-folders

Check infromation of CPU, memory and Hard Drive information

[CONTEXT]
In order to check the information of your CPU, memory and Disk usage.
[HOW]
To check your CPU information, just execute

$ cat /proc/cpuinfo
or
$ lscpu

To check your Memory information, just execute

$ cat /proc/meminfo

To check your Disk Usage information, just execute

$ df -h


[SOURCE]

man proc
man df

Removing annoying console beeps

In order, to remove the beep sound of your linux console just type the following command, in your console (in the directory /home/$your_user)

$echo 'set bell-style none' >> ~/.inputrc