The Linux Directories

10
Oct
0

The root (/) directory

The root directory begins with the / symbol

The /bin directory

This directory stores system binaries or programs used to oeprate the system. Non-critical programs or binaries are stored in the /usr/bin directory.

The /boot directory

This directory holds all the files needed to boot the system, except the configuration files. Files included are the kernal, boot loaders, and message files defining the text printed on the loading screen.

The /dev directory

This directory stores all devices used to access different hardware components in the system. Some devices are disk drives, floppy disks, tap drives, terminals, console, serial ports, parallel ports, and sound card.

To view devices currently connected on your computer

cd /dev

ls -lk

The /etc directory

This directory contains a variety of system configurations files needed for system initilization. All users can read files in this directory but only administrators can execute the files.

The /home directory

The /home directory is to store user’s home directory. The root’s home directory is located inside /root instead.

The /lib directory

This directory stores shared libraries allowing Linux’s executables to have smaller file size and denser features without the need of recompiling.

The /mnt directory

This directory to store references to external file systems or devices.

The  /opt directory

This directory is a holdover from Unix where /opt hosts additional or add-on software.

The /proc directory

This directory hold dynamic information generated from related system processes such as the kernal, network devices, etc…Each process is a folder with permission to access the process environment. Use ls -l to view long listing type of this folder.

ls -l

The /root directory

Not to be confused with the / directory, the /root directory is the home directory for root user.

The /sbin directory

This directory contains executables that can only be run by the root users. Many of these executables are essential for booting up the system.

The /tmp directory

This folder is used to store temporary files that lasts only a short period of time. This is an efficient way to manage files since most of these temporary files get deleted after a restart of the system or after a termination of a program.

The /usr directory

This directory is enormous that comes with a directory structure of its own.

The /usr/bin directory stores non-critical system executable files, even most of them are launched on a basis.

The /usr/dict directory stores spell checking command files.

The /usr/etc directory used to store configuration files but now no longer used for that purpose.

The /usr/games directory does not have to hold third party games but can be used for that purpose.

The /usr/include and /usr/lib are used to store the C compiler’s include and library files.

The /usr/sbin directory does not store critical system administration file.

The /var directory

Usually user mailboxes, system log files, and spool logs are stored in this directory.

The /var directory

The /var directory

lock – lock files for system processes

log – log files for login/logout, current users, syslog, httpd, ftpd, mail, and spool file.

run – files created for the current system run level.

spool – data that has been spooled for processing, such as print jobs.

state – system state variables.

Linux – setserial command

10
Oct
0

Serial ports on Linux are named ttyS followed by a number corresponding to the actual DOS COM port. For example

ttyS0 –> COM1
ttyS1 –> COM2
ttyS2 –> COM3
ttyS3 –> …you get the idea

The /dev directory holds information essential to operating these ports. setserial lists and configure the serial port configurations. To list all the serial ports, type

ls /dev/ttys*

setserial -g /dev/ttyS* prints out the configuration information for each serial port

Linux – date command

10
Oct
0

To change the date and time, type su, enter your password, then become root. Or sudo if you have a different setup.

You must adhere to the following format when setting date and time

MMDDhhmmCCYY.ss

MM 2 digits month
DD  2 digits day of the month
hh   2 digits hour in 24-hour clock format
mm 2 digits minute
CC  2 digits century
YY  2 digits  year
ss   2 digit seconds

For example: change the date and time to October 10 2008, 11:34:35 EDT

Change Date/Time

Change Date/Time

steps to successfully authenticate through an ISA Proxy on Linux

1
Oct
0

Who need this?

A person who is using Linux and try to authenticate himself/herself through Microsoft ISA Proxy.

Does Linux use ISA Proxy Authentication?

I’m not 100% sure but I know for a fact that even if you set System Proxy Settings, apt-get still is not going to work. I did some search on google and found that apt-get does not understand the algorithm used in the ISA server.

How to fix this?

Download, configure, and run NTLM, a program that enable apt-get to understand ISA Proxy Authentication algorithm.

Where to get this file?

http://sourceforge.net/project/showfiles.php?group_id=69259

Download and extract the gz file

Download the file then extract the folder onto your Desktop.

How to configure?

I’m using Ubuntu 8.0.4, the instruction may be different if you are using a different Linux flavor.

You can read the INSTALL file included in the package, but if you don’t want to you can read the image instruction (that’s why I’m writing this post).

Navigate to the NTLMaps folder using whichever method best suited for you. I’m a beginner so I use the GUI way.

NTLMaps Folder

NTLMaps Folder

Double click on the server.cfg to open up the file. Now you can configure your proxy. Now inside this file, there are many lines like the one below that allow you to configure your proxy settings. You will have to go through the entire text file to look for these lines.

Listening port on NTLMaps

Listening port on NTLMaps

Leave this port alone unless you want to use a different port.

Parent Proxy/Port

Parent Proxy/Port

Put your parent proxy address and port number here.

Windows domain

Windows domain

The text suggests that you should put only the NT Domain name, not full qualified domain name. I put my company’s full qualified domain name and it still works, your company may be different, try the full qualified domain name if the NT domain name does not work out for you.

Windows Username

Windows Username

Put your network log on name here. My company uses Windows logon username to authenticate through the proxy, your company may be different.

Windows Password

Windows Password

Put your network log on password here. My company uses Windows logon password to authenticate through the proxy, your company may be different.

Now the basic configuration is complete, how do I start this program?

Start Terminal, navigate to your NTLMaps folder, type python main.py to start the program

Start NTLMaps

Start NTLMaps

Now how do I tell Linux to direct all Microsoft proxy authentication to NTLMaps?

The instruction is also included in the server.cfg file but you can read the images if that’s better for you.

Network Proxy

Network Proxy

Network Proxy Configure

Network Proxy Configure

Navigate to SystemPreferencesNetwork Proxy and select Manual proxy configuration. Enter 127.0.0.1 for HTTP Proxy and port 5865. Make sure you also check the box “Use the same proxy for all protocols.”

Now you are done. All proxy authentication will not be directed back to NTLMaps for process.

Conclusion

This method WORKS. You can browse the internet as well as using apt-get. However, Website access is slower now since you have to authenticate again by going through NTLMaps.