Base Band

New posts about Base Band.

Earth Station

New posts about Earth Station.

Computer Networking

All posts about Computer Networking.

Product Review

New product reviews.

Disk Free (DF) Utility in Linux System




Disk Free (DF) Utility


# df --- Show the used and available disk space 

# free –m --- Show free and used RAM in megabyte

#free –g --- Show free and used RAM in giga bytes 

# bg --- To send a process to back ground

# fg --- To run a stopped process in the back ground


# top --- Details of all active process 

# ps --- Give the status of a process running for a user

# ps <PID_number> --- Give the status of a particular process 

# pidof  <process_name> --- Give the process ID (PID) of a process

# kill <PID_number> --- kill a process

# nice --- start a process with a given priority


# renice --- Change priority of an already running process

# df --- give free hard disk of your system

# free --- Tell the free RAM of your system

Kill Utility on Linux

                                                                              KILL Utility

# This utility is used to terminate the running process

# kill <PID_number> --- Kill the specific process

# Linux can process a lot of process at a time

# Nicenes has the value between -20 to 19

# The lower the niceness index, higher would be the priority, given to the task

# Default value of all the process is 0

# nice –n “nice_value” process name

# renice “nice_value” –p <PID_number>

# To prioritize the system we use nice value.

# The priority index of a process is called nice in linux. Its defaults valu is o and it can vary between 20 to -19

Miscillanious short note on Linux. Part-3




# karnel is the nucleus of the operating system and it communicate between hardware and software .

# Shell is a interprets use m which interprets user command through CLI like terminal.

# The bourne shell and the c shell are the most used shells in Linux

# Perl is a programming language specially used for script editing.

# Alt +Ctrl +F1 --- Number one virtual terminal.

# Alt +Ctrl +F2 --- Number two virtual terminal.

# Total 6 virtual terminal

# tty1 --- virtual terminal number one

# Alt + Ctrl + F7 --- Main terminal

# Arrow up --- Scroll up in history and enter to execute

# Arrow down --- Scroll down in history and enter to execue

# Ctrl + D --- Logout from the terminal

# Ctrl + Alt + del --- Reboot the system

# Every user has default umask value

# Depending on the umask value of the user in linux, default permission is set to file and directory .

# User cannot use the file and directory by the default permission.

# Default permission of file and directory of the user is 0664 and 0775

Short note about VI Editor in linux





VI Editor

# vi <file_name> --- It will create new file and open in command mode.

#After opening the vi in the command mode

   #i--- insert a cursor
   #a--- write after cursor
   #A--- write at the end of the line
   #ESC --- Terminate the insert mode
   #u--- Undo last change
   #U--- Undo all change to the entire line
   #O – Open a new file
   #dd--- delete a line
   #3dd--- Delete 3 line
   #D--- Delete contents of line after the courser
   #c--- Delete contents of line after the courser and inset new text
   #dw--- Delete word
   #4dw--- Delete 4 words
   #Cw--- change word
   #x--- Delete character at cursor
   #r--- replace cursor
   #R--- Overwrite charecter from the cursor on ward.
   #s--- Substitute one character under cursor continue to insert
   #S--- Substitute entire line and begin to insert at beginning at the line.
   #~ --- Change case of individual character.



Save and closing the file from vi editor

Shift +zz --- Save the file and quit
:w --- Save the file but keep it open
:q --- Quit without saving
:wq --- Save the file and quit
:x --- Save the file and quite