Linux Text Processing tools

Text Processing tools: (Grep/tail/cat/head/less)
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 X = Station No
 Y = Batch No

[student@desktopX ~]$ cd
[student@desktopX ~]$ mkdir linuxY/lesson03 -p
[student@desktopX ~]$ cd linuxY/lesson03/
[student@desktopX lesson03]$ ls
[student@desktopX lesson03]$ cp /etc/passwd .
[student@desktopX lesson03]$ ls
[student@desktopX lesson03]$ touch test
[student@desktopX lesson03]$ ls

[student@desktopX lesson03]$ cat test   
[student@desktopX lesson03]$ cat passwd
[student@desktopX lesson03]$ cat /etc/hostname

[student@desktopX lesson03]$ clear
[student@desktopX lesson03]$ echo hello        
[student@desktopX lesson03]$ echo hello > test
[student@desktopX lesson03]$ cat test
[student@desktopX lesson03]$ echo welcome > test        ; replace
[student@desktopX lesson03]$ cat test
[student@desktopX lesson03]$ echo hello world >> test    ; append
[student@desktopX lesson03]$ cat test
[student@desktopX lesson03]$ history
[student@desktopX lesson03]$ history > command-list
[student@desktopX lesson03]$ ls
[student@desktopX lesson03]$ cat command-list

[student@desktopX lesson03]$ cat passwd     ; concatinate
[student@desktopX lesson03]$ cat -n passwd     ; concatinate
[student@desktopX lesson03]$ less passwd    ; Scrolling
[student@desktopX lesson03]$ more passwd    ; file reading without cat (down)
[student@desktopX lesson03]$ head passwd   ; 1st 10 l ines
[student@desktopX lesson03]$ tail passwd    ; last 10 lines read

[student@desktopX lesson03]$ tail -5 passwd    ; last 5 lines
[student@desktopX lesson03]$ head -5 passwd    ; 1st 5 lines
[student@desktopX lesson03]$ cat -n passwd | tail -5

[student@desktopX lesson03]$ grep -n root passwd  ; search root keyword in passwd file
root:x:0:0:root:/root:/bin/bash
operator:x:11:0:operator:/root:/sbin/nologin

[student@desktopX lesson03]$ grep -n ^root passwd

[student@desktopX lesson03]$ tail passwd | grep root  ;search root keyword in last 10 lines
[student@desktopX lesson03]$ head passwd | grep root

[student@desktopX lesson03]$ cat -n passwd 
[student@desktopX lesson03]$ cut -d ":" -f 1 passwd
[student@desktopX lesson03]$ cut -d ":" -f 1,3 passwd
[student@desktopX lesson03]$ cut -d ":" -f 1-4 passwd
[student@desktopX lesson03]$ cut -d ":" -f 1 passwd > userlist
[student@desktopX lesson03]$ cat -n userlist

[student@desktopX lesson03]$ head passwd | grep root | cut -d ":" -f 1
 root
 operator

[student@desktopX lesson03]$ su
  :******
[root@desktopX lesson03]# cat -n /var/log/messages
[root@desktopX lesson03]# grep "Aug 29" /var/log/messages | cut -d " " -f 1-3 > log

[root@desktopX lesson03]# locate hosts
[root@desktopX lesson03]# updatedb
[root@desktopX lesson03]# locate sshd_config
[root@desktopX lesson03]# locate -i .jpg  ;including case sensitve
[root@desktopX lesson03]# find / -name root  ; root name file   
[root@desktopX lesson03]# find /var -type d -name mail  
[root@desktopX lesson03]# find / -type f -name passwd
[root@desktopX lesson03]# find / -size +100M   ; size more than 10MB
[root@desktopX lesson03]# find / -size -10M  ; size less than 10M
[root@desktopX lesson03]# find /home -name student -exec cp -rf {} /opt \;
[root@desktopX lesson03]# cd /opt
[root@desktopX opt]# ls

Working with "Help and Manual:"
==============================
[root@desktopX lesson03]# man passwd
[root@desktopX lesson03]# useradd --help

Online Documentation:
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 docs.redhat.com


    ----------------------  Thank you -----------------