find and replace

sed s/mysql/MySQL/2 snort.conf > snort2.conf

This command affects only the second occurrence of mysql.

kali >sed s/mysql/MySQL/g /etc/snort/snort.conf > snort2.conf

find and replace all of mysql

If you wanted to replace only the first occurrence of the term mysql, you would leave out the trailing g command.

Network attacks fall into one of three categories:

1.header avuses
2.network stack exploits
3.bandwidth saturation

Using the aux options to see processes for all users
ps aux

#top command
In many cases, we want to know which processes are using the most resources. This is where the top command comes in handy because it displays the processes ordered by resources used, starting with the largest.

Changing Process Priority with nice

When you start a process, you can set the priority level with the nice command and then alter the priority after the process has started running with the renice command.
#nice -n -10 /bin/slowprocess
when running
renice 20 6996

#start task in background
To start the text editor in the background, just append an ampersand (&) to the end of the command, like so:
command options &

Moving a Process to the Foreground
fg PID

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MANAGING USER ENVIRONMENT VARIABLES

ps xa | grep nginx

"searchtext" fileName.tex

cat iris.tex | grep "ad" | wc

find all file with extention text
ls | grep txt

rm filePath
rmdir direcotryPaht

ba carefull

rm -r directory
#remove dir and all file