UNIX

We may need to read run time variables, during the execution of a unix script. It is done with the help of read command. A few examples as below: server501:# echo “Enter Name: ” Enter Name: server501:# read name Angelina server501:# echo $name Angelina Some  other examples 1. server501:# #!/bin/sh server501:# …

Shell Scripting can be used for creating various scripts which help in complex  mathematical calculations or for UNIX operations. A few examples are given below: 1. To Compute square of n: 1. First open a file. server501:# vi square.sh Then ESC i, to go to insert mode Paste the code. n=1 while [ ${n} …

SED ( Stream editor) : A special editor for modifying files automatically. It has similarity with the “Find” and “Replace” command available in windows notepad/wordpad. sed command can be used to search and manipulate input text in many ways. Though mainly used for substitution, it can also do numerous other …

There are more than 200 UNIX level commands. The important ones are classified below: General Purpose Utilities passwd who whoami uname tty stty info Working With Directories mkdir rmdir ls File Handling Commands cat cp rm mv more wc cmp diff dos2unix tar gzip AND gunzip compress AND uncompress zip …

Awk actually stands for the names of its authors: “Aho, Weinberger, & Kernighan”. Used for pattern scanning / filtering Command syntax :   awk  <search pattern> { action } Example : Consider the file test.log with the below data server501:[DATA001] /home/oracle -> cat test.log ANJELINA IS A GOOD GIRL RAMU …

UNIX Architecture can be best understood if we know the components in UNIX. The important components of UNIX OS can be classified as below. 1. Kernel – small program written i n C which interacts with hardware 2.Shell (Command Interpretor) – One shell is generated for each user for running commands. Bourne shell(sh) is …

pwd                                       print working directory cd                                           change directory mkdir                                    make directory rmdir                                     remove directory ls                                             list contents of directory cat                                          display contents of files cp                                           copy one file to another rm                                          remove files tput clear                           clear screen who                                       …

The main divisions of UNIX components are: Kernel Shell Utilities External links: UNIX components

UNIX is the  trademarked form of Unics (Uniplexed Information and Computing System). UNIX is an important Operating System developed in 1969 by AT &T. Dennis Ritchie and Ken Thompson were the brains behind this OS. Though the  name UNIX is trademarked , UNIX is more like a family name now, …

CPU time/Process time is the amount of time  CPU spends processing instructions of a  program. This time doesnt include waiting for input/output operations. The CPU time is often measured in clock ticks or as a percentage of the CPU capacity. It is used as a measure of CPU usage by …

Central Processing System (CPU) is the part of computer which executes computer programs. To make it simple,a Program in execution is known as Process. The thing which we need to keep in mind always is that: Only one process can be executed per CPU/Core at a time. So if we …

CPU Utilization is the term used to denote the percentage of CPU utilized/used. 90 % CPU utilzation means 10% of CPU is still not used and is idle. CPU Load is the term which denotes the number of processes waiting to be scheduled for CPU. Its generally taken as the …