The /dev directory
You’ll see a lot of yellow outlined in black. These are the devices that your system uses or can use. Everything is considered a file in Linux, so your hard disk is kept track of as a file that sits there. If you’re using an IDE hard drive (as opposed to SCSI), your hard drive will be known as /dev/hda. Don’t delete that, because your hard disk will spin around, come jumping out of your computer, land on the floor and spill out ooze all over the place. No, not really. You will probably not have to look in /dev very much, so don’t worry about that.
The /dev directory is the location of special or device files. The /dev directory is populated with files as the kernel is recognising hardware.
when you will try to see the content of /dev
The /boot directory
cd /boot [ENTER]
Will get you into the /boot directory. You will not find any boots or shoes or footwear of any kind there. That’s where the Linux kernel usually is.
This directory contains everything required for the boot process except configuration files not needed at boot time and the map installer. Thus /boot stores data that is used before the kernel begins executing user-mode programs.
The operating system kernel must be located in either / or /boot.
Sub directories and files under /boot are: –
If you are not working as ‘root’ and you type cd /root, you will be taken to the directory /root. However, you won’t be able to do anything while you’re there. Root’s home directory is a restricted area for everybody else. Linux response is sort of like, ‘You don’t have to know that’. Users’ home directories are under certain restrictions for other users as well.
The /sbin directory
/sbin is another one of those off-limits directories. You may look, but you can’t touch. This directory is like /bin in that it has frequently used programs in it, but they’re only meant to be used by root. ‘Shutdown’ is in there. Only root can shutdown the system.
If a user other than root tried to shutdown the system, he or she would get a message saying that only root can do that.
The /tmp directory
/tmp is a directory that is used to store temporary files, as the name may suggest.
When you double-click on an icon of a photo, the photo comes up for you to see but a temporary file is created while you’re looking at the photo. The temporary file is deleted when you close the KDE image program. It’s mainly the programs that work under a windows manager that take advantage of this directory.
The /var directory
/var is a directory for certain files that may change their size (i.e. variable size).
For example, there are a few excellent databases for Linux. One is called MySQL. Normally, MySQL keeps its data in a subdirectory of /var called /var/mysql/. If I had an e-commerce website, I would have a database to register purchases. That database would obviously grow in size. And if it didn’t then I’d be in trouble. It is also the normal place where email servers store their incoming mail. Again, email varies in size as well.
The /lib directory
/lib is for library files.
Programs may use libraries to carry out their functions. Different programs use the same libraries, so Linux will store them here so that every program knows where to find them. You will probably not have to worry about this directory much unless you start getting messages like ‘can’t find shared library…’. That will sometimes happen when you’ve downloaded a program and had to compile it yourself from source. Even then, getting what are known as “dependency” problems are quite rare. Most programs, even when compiled from source, usually have a pre-configuration program that makes sure that they can find what libraries they “depend on” on to run. If they don’t, they’ll tell you that you can’t install the program.
The /home directory
This is a directory for storing users’ personal files.
All of us have certain preferences for using programs. These preferences are usually included in configuration files which are also stored in users’ home directories. Most of these files start with a ‘.’ (period/dot).