Commands by rubo77

Commands by rubo77 (8)

sorted by

Generat a Random MAC address

Generate a random MAC address with capital letters
This is sample output - yours may be different.
3

hexdump -n6 -e '/1 ":%02X"' /dev/random|sed s/^://g

rubo77 · 2015-01-19 03:09:43 9
View all new log messages in real time with color

This will show all changes in all log files under /var/log/ that are regular files and don't end with `gz` nor with a number Show Sample Output
This is sample output - yours may be different.
```
==> /var/log/auth.log <== 

==> /var/log/mail.log <== 

==> /var/log/auth.log <== 
Jul 29 19:07:30 yourhost sshd[7915]: Connection closed by 127.0.0.1 [preauth] 
```
4

find /var/log -type f -iregex '.*[^\.][^0-9]+$' -not -iregex '.*gz$' 2> /dev/null | xargs tail -n0 -f | ccze -A

rubo77 · 2014-07-29 17:11:17 5
replace text in all files in folder, into subfolder

if you want to replace "foo" with "bar" in all files in a folder, and put the resulting files into a new subfolder
This is sample output - yours may be different.
-5

mkdir replaced;for i in *; do cat "$i"| sed 's/foo/bar/' > "replaced/$i"; done

rubo77 · 2011-08-30 08:28:26 6
List your MACs address
This is sample output - yours may be different.
6

ifconfig eth0 | grep -o -E '([[:xdigit:]]{1,2}:){5}[[:xdigit:]]{1,2}'

rubo77 · 2011-04-28 18:33:45 5
add random color and external ip address to prompt (PS1)

this adds a random color to your prompt and the external ip. useful if you are using multiple mashines with the same hostname. Show Sample Output
This is sample output - yours may be different.
```
user@host^192.168.0.1:~$ 
```
0

IP=$(nslookup `hostname` | grep -i address | awk -F" " '{print $2}' | awk -F# '{print $1}' | tail -n 1 ); R=3$((RANDOM%6 + 1)); PS1="\n\[\033[1;37m\]\u@\[\033[1;$R""m\]\h^$IP:\[\033[1;37m\]\w\$\[\033[0m\] "

rubo77 · 2010-10-20 07:29:14 8
show large folders and files, including hidden

shows only folders, that are MB or GB in total size
This is sample output - yours may be different.
-2

du -shc .[^.]* * | grep [MG]

rubo77 · 2010-07-06 10:13:18 14
Unique number by Mac Address

gets the last number of the mac address to use it for other stuff Show Sample Output
This is sample output - yours may be different.
```
$ echo $UNIQUE_BY_MAC
213
```
-3

UNIQUE_BY_MAC=$(ifconfig |grep eth0|awk '{ print strtonum("0x"substr($6,16,2)) }')

rubo77 · 2010-06-01 17:34:43 11
read unixtimestamp with festival

you will hear how many seconds since 1.1.1970 in english words with billions, millions and thousands. this is very useful, if you want to get over to use the unixtimestamp instead of the 24 hour clock in your dayly life Show Sample Output
This is sample output - yours may be different.
```
1275038122
```
1

say='festival --tts'; S=$(date +%s); echo $(echo $S | cut -b 1-1)" billion" | $say ; echo $(echo $S | cut -b 2-4 | sed 's/0*//')" million"| $say; echo $(echo $S | cut -b 5-7 | sed 's/0*//')" thousand"| $say

rubo77 · 2010-05-28 09:19:24 4

What's this?

commandlinefu.com is the place to record those command-line gems that you return to again and again. That way others can gain from your CLI wisdom and you from theirs too. All commands can be commented on, discussed and voted up or down.

Share Your Commands

Check These Out

Converts uppercase chars in a string to lowercase

List the size (in human readable form) of all sub folders from the current location

Tested on MacOS and GNU/Linux. It works in dirs containing files starting with '-'. It runs 'du' only once. It sorts according to size. It treats 1K=1000 (and not 1024)

Find usb device in realtime

Using this command you can track a moment when usb device was attached.

Show contents of all git objects in a git repo

This script finds all git objects and `git cat-file`'s their content. This is really just a helper function to play around with the internals of git repositories. See https://git-scm.com/book/en/v2/Git-Internals-Git-Objects of more info.

Numbers guessing game

Felt like I need to win the lottery, and wrote this command so I train and develop my guessing abilities.

Download all manuals RedHat 7 (CentOS/Fedora) with one command in Linux

Colorize grep output

Which processes are listening on a specific port (e.g. port 80)

swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

Find all active ip's in a subnet

nmap for windows and other platforms is available on developer's site: http://nmap.org/download.html nmap is robust tool with many options and has various output modes - is the best (imho) tool out there.. from nmap 5.21 man page: -oN/-oX/-oS/-oG : Output scan in normal, XML, s|

Host cpu performance

Measure the cpu performance: In-case if the cpu is thermal throttling then you can find it using this command. Check the first line of the output. Example: Doing md5 for 3s on 16 size blocks: 11406892 md5's in 2.98s ? #(When cpu is not throttling) Doing md5 for 3s on 16 size blocks: 110692 md5's in 2.98s ?? #(When cpu is thermal throttling) Practical use case: Once we had cooling outage in data center which caused thermal throttling in some of the worker nodes. We used this tool to prove that some servers are not performing well because of the cpu thermal throttling.

Stay in the loop…

Follow the Tweets.

Every new command is wrapped in a tweet and posted to Twitter. Following the stream is a great way of staying abreast of the latest commands. For the more discerning, there are Twitter accounts for commands that get a minimum of 3 and 10 votes - that way only the great commands get tweeted.

» http://twitter.com/commandlinefu
» http://twitter.com/commandlinefu3
» http://twitter.com/commandlinefu10

Subscribe to the feeds.

Use your favourite RSS aggregator to stay in touch with the latest commands. There are feeds mirroring the 3 Twitter streams as well as for virtually every other subset (users, tags, functions,…):

Subscribe to the feed for:

» all commands
» commands with 3 up-votes (commandlinefu3)
» commands with 10 up-votes (commandlinefu10)
» commands by rubo77