Linux and networking

Linux Shortcuts Keys For vim Editor 1. Go to the first line gg or 1 shift g or :0 (zero) Enter 2. Go to the last line. Shift g or :$ Enter 3. Go to line 8 8 shift g 4. To scroll down one screen Ctrl f 5. To scroll up one screen Ctrl b 6. First position on line 0(zero) 7. Last position on line $ 8. Go to matching parenthesis % 9. Right, left, up, down respectively. l, h, k, j Or You can also use arrow keys 10. Where Am I? Ctrl g ********************** 1. Copying a whole line yy or shift y or :ny where n is the number of line if n is not specified then copy the current line 2. Copying from current position to end of line. y$ 3. Copying 3 lines after the current position 3yy 4. Copying a range of line :1,5y or :1y 5 The above example copy 5 lines, from 1 to 5 5. Deleting a whole line (Deleted line is copy to the registers) dd or :nd Where n is the number of line if n is not specifie...

Step 1: Download you can download Linux version of XAMPP from the give link A complete list of downloads (older versions) is available Step 2: Installation After downloading simply type in the following comm ands: Go to a Linux shell and login as the system administrator root: su Extract the downloaded archive file to /opt: tar xvfz xampp-linux-1.7.tar.gz -C /opt Note: Please use only this command to install XAMPP. DON'T use any Microsoft Windows tools to extract the archive, it won't work. Note : already installed XAMPP versions get overwritten by this command. That's all. XAMPP is now installed below the /opt/lampp directory. Step 3: Start To start XAMPP simply call this command: /opt/lampp/lampp start You should now see something like this on your screen: Starting XAMPP 1.7... LAMPP: Starting Apache... LAMPP: Starting MySQL... LAMPP started. Ready. Apache and MySQL are running. If you get any error messages please take a look at the Step 4:...

Date : Shows the current date and Time. Cal : Shows this month's calendar. uptime :  Show current Uptime. W : Displays who is online. whoami : Displays user's information. uname -a : Show Kernal information. cat /proc/cpuinfo : Cpu information. cat /proc/meminfo : Menory information. df : Show disk usage. du : Show directory space usage. free : Show memory and Swap usage  whereis app : Show possible locatins of app which app : show which app will be run by default

STEP 1: now open the file #vim /etc/wvdial.conf STEP 2: erase all the content of this file and paste following lines [Modem0] Modem = /dev/ttyACM0 Baud = 115200 SetVolume = 0 Dial Command = ATDT Init1 = ATZ Init3 = ATM0 FlowControl = CRTSCTS [Dialer airtel] Username = a Password = a Phone = *99# Stupid Mode = 1 Init1 = ATZ Init2 = ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0 Init3 = AT+CGDCONT=1,"IP"," airtelgprs. com " Inherits = Modem0 :wq! save and exit STEP 3: #vim /etc/resolv.conf nameserver 202.56.250.5 :wq! save and exit STEP 4: Now open another terminal and run this command #wvdial airtel and minimized it

chmod : The chmod command allows you to alter access rights to files and directories. the shell prompt type: ls -alt You should see some files with the following in front of them example: drwxrwsr-x 7 rajesh 1024 Apr 6 14:30 drwxr-s--x 22 rajini 1024 Mar 30 18:20 d-wx-wx-wx 3 Cheguevara1024 Apr 6 14:30 What do the letters mean in front of the files/directories mean? r indicates that it is readable w indicates that it is writable x indicates that it is executable - indicates that no permission to manipulate has been assigned When listing your files, the first character lets you know whether you’re looking at a file or a directory. It’s not part of the security settings. The next three characters indicate Your access restrictions. The next three indicate your group's permissions, and finally other users' permissions. chmod 755 filename The example above will grant you full rights, group rights to execute and read, and all others access to execute the file. 7 permission Fu...

Permissions For security reasons, all Unix systems including Linux have file permissions which allow you to control access to directories - who can read, write, or execute a file or command in a directory. In the extreme left is either a d or hyphen (-) indicating whether this is a directory or a file (occasionally you will also see an l indicating a link). Then you see three groups of the same three letters in the same order: r for read, w for write, x for execute, and the hyphen (-) for no permission given in that type. The first group of three letters is for the owner, the second group for the group, and the third the world. Whoever creates the file is the owner, and if more than one person is working on a project or needs access to this file they are given permission as a group, and finally how the file is open to anyone who has access to the system (the world). chmod, chown, chgrp The command to change file permissions is chmod (change mode). There are two ways for do...

command cd : Use cd change directories example: cd home or complete path must be written cd /root/home command clear : clean up your command window command ls : The ls command lists the contents of your current working directory command mkdir : makes directory command df : df provides a very quick check of your file system disk space. command du : du display usage of the disk space example du -a command finger : finger allows you to see who else is on the system or get detailed information about a person who has access to the system. command man : man followed by a command will give detailed information about that command Example: man ls command logout : logout will log your account out of the system command find : find will locate a files/directories qui...