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Setup nginx on centos7

make sure nginx service is up and running

curl http://localhost

should return welcome centos html text

add firewall rule(if firewall is on)


awk is mini language for text processing . could be useful when filtering columns or rows

sample text file

filter row

filter column


the samples text file


linux command with samples

Grep

find all log files

count how many log files

grep keyword in file

grep keyword in file and use -n to print line number

grep…


Install apache marialDB php

Apache

If you have nginx installed. need to stop it first (systemctl stop nginx)

MarialDB

Php

test installation

add line

curl http://localhost/info.php

Install Zabbix


Clone and build modsecurity


Linux file system directory structure

bin : user binary files

boot : include files needed when boot system

dev : devices , appear as files

etc : system wide configuration files . user specific configuration file located in each user/home

home : home folder of each user

lib : system libraries . user specific library…


Process life cycle

fork and exec

Fork : Create a separate duplicated process (child process memory space copied from parent )

Exec : create a process replace current entire process (replace pid)

creation

All process created from parent process except ‘init’

Init process created by os kernel , id= 1 , which is the root process (systemd)

Subprocess.popen and os.fock in python


Virtual Memory

In linux there is mapping between virtual address and physical address to abstract application’s memory usage .

How it works

Each program maintain a mapping . what it brings :

#1 if not enough physical memory .could map to disk

#2 memory “hole” on physical memory . each program could…

LORY

Software Developer/Technical Writer&Author/body builder

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