Skip to main content

Linux Commands Directory

Why Bother?

Why do you need to learn the command line anyway? Well, let me tell you a story. A few years ago we had a problem where I used to work. There was a shared drive on one of our file servers that kept getting full. I won't mention that this legacy operating system did not support user quotas; that's another story. But the server kept getting full and it stopped people from working. One of our software engineers spent the better part of a day writing a C++ program that would look through all the user's directories and add up the space they were using and make a listing of the results. Since I was forced to use the legacy OS while I was on the job, I installed a Linux-like command line environment for it. When I heard about the problem, I realized I could do all the work this engineer had done with this single line:


du -s * | sort -nr > $HOME/user_space_report.txt
 
Graphical user interfaces (GUIs) are helpful for many tasks, but they are not good for all tasks. I have long felt that most computers today are not powered by electricity. They instead seem to be powered by the "pumping" motion of the mouse! Computers were supposed to free us from manual labor, but how many times have you performed some task you felt sure the computer should be able to do but you ended up doing the work yourself by tediously working the mouse? Pointing and clicking, pointing and clicking.
I once heard an author say that when you are a child you use a computer by looking at the pictures. When you grow up, you learn to read and write.

Here is a complete linux command reference:

Linux Command Directory



Comments

Popular posts from this blog

AMD Radeon™ HD 7670M on Ubuntu 12.04

Update:  Recently I install kubuntu 13.10 and there is no problem with graphics. It just works  fine out of the box.
I've seen many blog posts on how to make AMD HD7670M work on Ubuntu 12.04, specially when its in switchable graphics board like Dell Inspiron 15R 5520. I tried many things to make it work so that I could use the cinnamon desktop on ubuntu & other things too.. But to my surprise even the drivers from AMD site didn't work.
Then I tried a combination of those blog posts I read & somehow I became successful in running the full graphics including compiz settings inside My Ubuntu Machine.
Following are the steps I followed & it worked...
1. Create a backup of your xorg configuration file:
sudo cp /etc/X11/xorg.conf /etc/X11/xorg.conf.BAK
2. Remove/purge current fglrx and fglrx-amdcccle :
sudo apt-get remove --purge fglrx*
3. Install the driver:
sudo apt-get install fglrx fglrx-amdcccle
4. Install additional components for advanced graphics:
sudo apt-get install xvba-…

Shell Script: Find Number Of Arguments Passed

Many times , when we create shell scripts we try to do repetitive tasks through functions. Some functions take arguments & we have to check the no. of arguments that are passed to it.

Each bash shell function has the following set of shell variables:
[a] All function parameters or arguments can be accessed via $1, $2, $3,..., $N. [b] $* or $@ holds all parameters or arguments passed to the function. [c] $# holds the number of positional parameters passed to the function. [d] An array variable called FUNCNAME ontains the names of all shell functions currently in the execution call stack. ExampleCreate a shell script as follows: #!/bin/bash # Purpose: Demo bash function # ----------------------------- ## Define a function called test() test(){   echo "Function name:  ${FUNCNAME}"   echo "The number of positional parameter : $#"   echo "All parameters or arguments passed to the function: '$@'"   echo }
## Call or invoke the function ## ## Pass the parameters or a…

CentOS / Redhat : Configure CentOS as a Software Router with two interfaces

Linux can be easily configured to share an internet connection using iptables. All you need to have is, two network interface cards as follows:
a) Your internal (LAN) network connected via eth0 with static ip address 192.168.0.1
b) Your external WAN) network is connected via eth1 with static ip address 10.10.10.1  ( public IP provided by ISP ) Please note that interface eth1 may have public IP address or IP assigned by ISP. eth1 may be connected to a dedicated DSL / ADSL / WAN / Cable router: Step # 1: Enable Packet ForwardingLogin as the root user. Open /etc/sysctl.conf file # vi /etc/sysctl.conf
Add the following line to enable packet forwarding for IPv4: net.ipv4.conf.default.forwarding=1
Save and close the file. Restart networking: # service network restart
Step # 2: Enable IP masquerading
In Linux networking, Network Address Translation (NAT) or Network Masquerading (IP Masquerading) is a technique of transceiving network traffic through a router that involves re-writing the source and/or d…