Friday, December 23, 2011

Command Line Tips

Here is some of command line tricks that can help you a lot.
I am working on this post So you will get more and more...

1.) Using vim to see Calender of two years in single window.

#vim -O <(cal 2011) <(cal 2012)
Here -O     Open  one window for each file.

2.) ifconfig eth0;sleep 60;ifconfig eth0)|grep "RX bytes"

# Pass two runs of ifconfig 60 seconds apart through the same grep using a subshell.

[root@server2 ~]#(ifconfig eth0;sleep 60;ifconfig eth0)|grep "RX bytes"
          RX bytes:332299170 (316.9 MiB)  TX bytes:21752930 (20.7 MiB)
          RX bytes:337602454 (321.9 MiB)  TX bytes:21927669 (20.9 MiB

3.) Here is One line coding for getting status of all init.d scripts(services) and store result in a file

root@primary ~] for i in /etc/init.d/*; do echo -e $i status:; echo -e "\t";$i status ;echo -e "\n"; done > ~/daemon_status_list

Dated : 19-Oct-2011
4.) Command to display list of top files or directories size wise.

#for X in $(du -s * | sort -nr | cut -f 2| head -n 2); do     du -hs $X; done 

5.) Execute a command at a given time
#echo "ls -l" | at
e.g. Suppose you want to dispaly the list of current working directory at your current terminal. then use following command:
#echo "ls -l > $(tty)" | at 13:46

You can also make use of this trick according to your requirements.


6) Using column Command:




7.) Using Regular Expression to exclude some of Directories.
[root@test]~# ll -d  /*
drwxr-xr-x   2 root   root      4096 May 31 04:02 /bin
drwxr-xr-x   3 root   root      1024 May 29 00:17 /boot
drwxr-xr-x   3 root   root      4096 May 28 02:33 /customer
drwxr-xr-x  12 root   root      3660 Sep 19 03:28 /dev
drwxr-xr-x  88 root   root     12288 Nov 16 06:49 /etc
drwxr-xr-x   2 root   root      4096 Aug  8  2008 /home
drwxrwxrwx  17 root   root      4096 Oct 31 03:37 /local
dr-xr-xr-x 395 root   root         0 Sep 18 23:26 /proc


Exclude all directory starting from d,p and l
[root@ph132704]~# ll -d  /[!d,p,l]*
drwxr-xr-x  2 root   root      4096 May 31 04:02 /bin
drwxr-xr-x  3 root   root      1024 May 29 00:17 /boot
drwxr-xr-x  3 root   root      4096 May 28 02:33 /customer
drwxr-xr-x 88 root   root     12288 Nov 16 06:49 /etc
drwxr-xr-x  2 root   root      4096 Aug  8  2008 /home

This can be helpful while using du and want to exclude some directories.
[root@test]~# du -sh /[!c-z]*
7.7M    /bin
19M     /boot


!Enjoy CLI Mode

Excuse for typo
Kuldeep Sharma









2 comments:

  1. its intersting but how we move cursor from 1st one to 2nd one.............

    ReplyDelete
  2. Hi,
    Would you please explain"how we move cursor from 1st one to 2nd one" in detail?

    Thanks,
    Kuldeep

    ReplyDelete

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