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 12
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 07:20:37 127
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 9
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 5

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Pulls email password out of Plesk database for given email address.

This simply pulls the password out of the database for the given mail name for ease of use in testing emails that you would not normally have access to.

poor man's vpn

this easy to install tool redirects all traffic to internet through ssh. it's very usefull when connecting to free wifi. you need to start it as root because it needs permissions to change iptables settings. ofcourse you also need a shell account

send DD a signal to print its progress

every 1sec sends DD the USR1 signal which causes DD to print its progress.

Show the total number of changes that every user committed to a Subversion repository

This saves Subversion's log output as XML and then runs an XQuery over it. This is standard XQuery 1.0 and should therefore also work with other XQuery processors. I have tested it with Zorba (http://www.zorba-xquery.com). XQilla (http://xqilla.sourceforge.net) also does it, but you'd have to save the query to a file and then execute "xqilla filename.xq". The query first finds all distinct authors and then, for each author, sums up the number of paths they have changed in each commit. This accounts for commits of multiple changes at once. The indenting space in all lines from the second one seems to be due to a bug in Zorba.

Join lines split with backslash at the end

Joins each line that end with backslash (common way to mark line continuation in many languages) with the following one while removing the backslash.

Draw kernel module dependancy graph.

parse `lsmod' output and pass to `dot' drawing utility then finally pass it to an image viewer

SVN script for automatically adding and deleting files

Delete all aliases for a network interface on a (Free)BSD system

The example command deletes all aliases for network interface 'em0' assuming that the aliases have netmask of 255.255.255.255 and the master IP has some other netmask (such as 255.255.255.0). See here -> http://my.galagzee.com/2009/07/22/deleting-all-network-interface-aliases/ for more on the rationale of this command.

Leap year calculation

Create the signature base string required for a Twitter stream feed

This is the SECOND command in a set for five that are needed for a Twitter stream feed. This command creates variable "b", the so-called "base string" required for oauth in Twitter stream feed requests. (The 256 char limit prevents giving it a better name) We use five environment variables created by a previous step: id, k1, once, ts and k3. The five environment variables are created in a separate command, please see my other commands. For more information on the signature base string, see dev.twitter.com/apps, click on any app (or create a new one) and then go to the "OAuth Tool" tab.

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Commands by wejn (9)

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