cogito ergo sum

Red Hat Linux offers a wonderful graphical interface for the desktop, a long with many capable graphical administration tools, but you can’t manage or use Linux effectively if you don’t know how to use text-based programs at the command line.

Some of the basic command-line skills covered in these modules include

1. Performing routine tasks – Logging in and out, using the text console, changing password, listing and navigating directories
2. Basic file management – Creating, renaming, or deleting files and directories.
3. Basic user management – creating or deleting user from command line
4. Basic system management – Shutting down or rebooting, reading manual pages or other documentation, and using text-based tools to edit system configuration files.

Viewing the Red Hat Linux File System

[root@dosen-abs /]# ls /

bin dev home lib misc opt root tmp var

boot etc initrd lost+found mnt proc sbin usr

[root@dosen-abs /]#

To get a more detailed picture, use tree command

[root@dosen-abs /]# tree -dx /|less

/

|– bin

|– boot

| `– grub

|– dev

| |– ataraid

| |– cciss

| |– compaq

| |– cpu

.

.

If you can’t run tree command, then you should install it from red hat package manager, find tree package on CD 3: Use these steps to install tree-1.2-22.i386.rpm package:

[root@dosen-abs /]# mount /dev/cdrom /mnt/cdrom/

mount: block device /dev/cdrom is write-protected, mounting read-only

[root@dosen-abs /]# cd /mnt/cdrom

[root@dosen-abs cdrom]# ls

EULA GPL README RedHat RPM-GPG-KEY TRANS.TBL

[root@dosen-abs cdrom]# cd RedHat/RPMS

[root@dosen-abs RPMS]# rpm -ivh tree-1.2-22.i386.rpm

warning: tree-1.2-22.i386.rpm: V3 DSA signature: NOKEY, key ID db42a60e

Preparing… ########################################### [100%]

package tree-1.2-22 is already installed

[root@dosen-abs RPMS]#

Basic Linux Directories

Name
Description

/
The root directory

/bin
Essentials command

/boot
Boot loader files, Linux kernel

/dev
Device files

/etc
System configuration files

/home
User home directories

/lib
Shared libraries, kernel modules

/mnt
Usual mount point for local, remote file systems

/opt
Add-on software packages

/proc
Kernel information, process control

/root
Superuser (root home)

/sbin
System commands (mostly root only)

/tftpboot
Network boot support

/tmp
Temporary files

/usr
Secondary software file hierarchy

Use and Edit Files in the /etc Directory

More than 20MB of system configuration files and directories reside under the /etc directory if you install all the software packages, such apache, openssh and xinetd, have directories configuration files under /etc.

Other important system-related configuration files in /etc are

fstab – the system filessytem table is a text file listing each hard drive, CD-ROM, floppy or other storage device attached to your PC.
inittab – the system initialization table defines the default runlevel. Changes to this file can determine whether your system boots to a graphical or text login.
modules.conf – This configuration file containts directions and options used when loading kernel modules to enable various types of hardware, such as sound, USB, networking, and so on.
passwd – the list of user for the system, along with password and account information
printcap – the system’s printer capabilities database
shells – a list of approved shells

One of the most important directories under /etc for Red Hat Linux is sysconfig. This directory contains network activation scripts and hardware and software-related information:

[root@dosen-abs RPMS]# tree -afx /etc/sysconfig|less

/etc/sysconfig

|– /etc/sysconfig/apm-scripts

| `– /etc/sysconfig/apm-scripts/apmscript

|– /etc/sysconfig/apmd

|– /etc/sysconfig/authconfig

|– /etc/sysconfig/clock

|– /etc/sysconfig/console

|– /etc/sysconfig/desktop

|– /etc/sysconfig/devlabel

|– /etc/sysconfig/firstboot

|– /etc/sysconfig/gpm

|– /etc/sysconfig/grub

|– /etc/sysconfig/harddisks

|– /etc/sysconfig/hwconf

|– /etc/sysconfig/i18n

|– /etc/sysconfig/init

|– /etc/sysconfig/installinfo

|– /etc/sysconfig/iptables

|– /etc/sysconfig/irda

|– /etc/sysconfig/keyboard

|– /etc/sysconfig/kudzu

|– /etc/sysconfig/mouse

|– /etc/sysconfig/named

|– /etc/sysconfig/network

|– /etc/sysconfig/network-scripts

| |– /etc/sysconfig/network-scripts/ifcfg-eth0

| |– /etc/sysconfig/network-scripts/ifcfg-lo -> ../networking/ifcfg-lo

| |– /etc/sysconfig/network-scripts/ifdown -> ../../../sbin/ifdown

| |– /etc/sysconfig/network-scripts/ifdown-aliases

| |– /etc/sysconfig/network-scripts/ifdown-ippp

| |– /etc/sysconfig/network-scripts/ifdown-ipv6

| |– /etc/sysconfig/network-scripts/ifdown-isdn -> ifdown-ippp

| |– /etc/sysconfig/network-scripts/ifdown-post

| |– /etc/sysconfig/network-scripts/ifdown-ppp

| |– /etc/sysconfig/network-scripts/ifdown-sit

| |– /etc/sysconfig/network-scripts/ifdown-sl

| |– /etc/sysconfig/network-scripts/ifup -> ../../../sbin/ifup

| |– /etc/sysconfig/network-scripts/ifup-aliases

| |– /etc/sysconfig/network-scripts/ifup-ippp

| |– /etc/sysconfig/network-scripts/ifup-ipv6

| |– /etc/sysconfig/network-scripts/ifup-ipx

| |– /etc/sysconfig/network-scripts/ifup-isdn -> ifup-ippp

| |– /etc/sysconfig/network-scripts/ifup-plip

| |– /etc/sysconfig/network-scripts/ifup-plusb

| |– /etc/sysconfig/network-scripts/ifup-post

| |– /etc/sysconfig/network-scripts/ifup-ppp

| |– /etc/sysconfig/network-scripts/ifup-routes