Commands by wejn

Commands by wejn (9)

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Print the IPv4 address of a given interface
This is sample output - yours may be different.
3

ip a s eth0 | awk -F'[/ ]+' '/inet[^6]/{print $3}'

wejn · 2014-10-13 18:33:38 9
dpkg: purge all packages matching some name

Recently in Debian Wheezy the dpkg command refuses to work with wildcards, so this is the one-liner alternative. (alternative to #13614)
This is sample output - yours may be different.
0

sudo dpkg -P $(dpkg -l yourPkgName* | awk '$2 ~ /yourPkgName.*/ && $1 ~ /.i/ {print $2}')

wejn · 2014-08-06 22:40:32 9
Extract domain from URl

Extracts 2nd-level domain part (or 3rd level, for co.* or com.*) from the URI's hostname. See sample output. Show Sample Output
This is sample output - yours may be different.
```
# not output itself but example mapping of ARGV[0] to output
http://test.example.com/something/here -> example.com
http://test.example.co.uk/something/else -> example.co.uk
http://test.example.com.cz/something/else -> example.com.cz
```
1

ruby -ruri -e 'u=URI(ARGV[0]).host.split("."); puts u[(u[-2] =~ /^com?$/ ? -3 : -2)..-1].join(".")' http://test.example.com

wejn · 2014-05-25 18:43:44 7
Displays the number of processes per state
This is sample output - yours may be different.
3

while true; do clear;awk '{a[$3]+=1};END{for(x in a){print x,a[x]}}' /proc/[0-9]*/stat; sleep 1; done

wejn · 2014-05-24 21:04:41 8
Extract shortcuts and hostnames from .ssh/config

Spits out table that shows your Host->HostName aliases in ~/.ssh/config
This is sample output - yours may be different.
3

awk '$1=="Host"{$1="";H=substr($0,2)};$1=="HostName"{print H,"$",$2}' ~/.ssh/config | column -s '$' -t

wejn · 2014-05-24 20:51:47 7
truncate deleted files from lsof

While the posted solution works, I'm a bit uneasy about the "%d" part. This would be hyper-correct approach: lsof|gawk '$4~/txt/{next};/REG.*$deleted$$/{sub(/.$/,"",$4);printf ">/proc/%s/fd/%s\n", $2,$4}' Oh, and you gotta pipe the result to sh if you want it to actually trim the files. ;) Btw, this approach also removes false negatives (OP's command skips any deleted files with "txt" in their name).
This is sample output - yours may be different.
1

lsof|gawk '$4~/txt/{next};/REG.*$deleted$$/{printf ">/proc/%s/fd/%d\n", $2,$4}'

wejn · 2014-03-11 10:40:32 13
Convert JSON to YAML

Show Sample Output
This is sample output - yours may be different.
```
Note: you need Ruby 1.9 or better
```
11

ruby -ryaml -rjson -e 'puts YAML.dump(JSON.parse(STDIN.read))' < file.json > file.yaml

wejn · 2013-04-24 07:20:37 128
Show number of connections per remote IP

Output contains also garbage (text parts from netstat's output) but it's good enough for quick check who's overloading your server.
This is sample output - yours may be different.
-1

netstat -antu | awk '{print $5}' | awk -F: '{print $1}' | sort | uniq -c | sort -n

wejn · 2013-04-08 19:46:41 10
Show header HTTP with tcpdump

This is a better way to do the "src X or dst X" filter; plus you might not want to bother with DNS lookups (-n).
This is sample output - yours may be different.
-1

tcpdump -s 1024 -l -A -n host 192.168.9.56

wejn · 2013-02-02 22:29:52 6

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Calculate the distance between two geographic coordinates points (latitude longitude)

The Haversine formula determines the great-circle distance between two points on a sphere given their longitudes and latitudes.

The scene in the Shining (Stanley Kubrick)

Let's take a rest. How about watch a horror? The Shining http://en.wikipedia.org/wiki/The_Shining_(film)

Get AWS temporary credentials ready to export based on a MFA virtual appliance

You might want to secure your AWS operations requiring to use a MFA token. But then to use API or tools, you need to pass credentials generated with a MFA token. This commands asks you for the MFA code and retrieves these credentials using AWS Cli. To print the exports, you can use: `awk '{ print "export AWS_ACCESS_KEY_ID=\"" $1 "\"\n" "export AWS_SECRET_ACCESS_KEY=\"" $2 "\"\n" "export AWS_SESSION_TOKEN=\"" $3 "\"" }'` You must adapt the command line to include: * $MFA_IDis ARN of the virtual MFA or serial number of the physical one * TTL for the credentials

List the biggest accessible files/dirs in current directory, sorted

Recursive Ownership Change

Changing files ownership in a directory recursivley from a user to another

Finding the number of cpu's

Show most common words in filenames

I'm sure there's a more elegant sed version for the tr + grep section.

sends your internal IP by email

This is useful if you have need to do port forwarding and your router doesn't assign static IPs, you can add it to a script in a cron job that checks if you IP as recently changed or with a trigger script. This was tested on Mac OSX.

Open (in vim) all modified files in a git repository

The option --porcelain makes the output of git easier to parse. This one-liner may not work if there is a space in the modified file name.

Save your terminal commands in bash history in real time

Use this command if you want your terminal commands be saved in your history file in real time instead of waiting until the terminal is closed

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Commands by wejn (9)

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