Commands by forcefsck

Commands by forcefsck (8)

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Find out the installation time of a linux system (when installed in a ext2/3/4 file system)

Find out the earliest installation time of a linux system by getting the / filesystem creation time. This example is only valid the os is installed on an ext2/3/4 filesystem.
This is sample output - yours may be different.
0

tune2fs -l $(df -P / | awk 'NR==2 {print $1}') | sed -n 's/^.*created: *//p'

forcefsck · 2012-05-31 12:12:35 4
encode/decode HTML entities

For reverse, there's asc2xml asc2xml < entitiesfile > utf8file They come as a part of the html-xml-utils debian package. PS. Tried to submit sample data, but the site autoconverted the non ascii to html entities. So a bit of imagination is needed. Show Sample Output
This is sample output - yours may be different.
```
$ echo "foo somegreekchars bar" | xml2asc
foo &#945;&#946;&#947;&#948; bar

$ echo "foo &#945;&#946;&#947;&#948; bar" | asc2xml 
foo somegreekchars bar
```
-3

xml2asc < inputfile > outputfile

forcefsck · 2011-02-23 12:22:18 5
Rename files in a directory in an edited list fashion

just an alternative to #7818 Show Sample Output
This is sample output - yours may be different.
```
Rename file: 1one
To: 1one.txt
`1one' -> `1one.txt'
Rename file: 2two
To: one plus one
`2two' -> `one plus one'
Rename file: 3three
To: 3three
Rename file: 4four
To: 2 x 2
`4four' -> `2 x 2'
Rename file: 5five
To: 5five.avi
`5five' -> `5five.avi'
```
0

exec 3<&0; ls -1N | while read a; do echo "Rename file: $a"; read -e -i "$a" -p "To: " b <&3 ; [ "$a" == "$b" ] || mv -vi "$a" "$b"; done

forcefsck · 2011-02-08 21:21:39 199
Display any udp/tcp connections by process name or by process id

Where COMMAND is the process(es) name. I prefer to get all states but you may add ESTABLISHED in the grep regex. lsof -c apache2 | egrep -o 'TCP.*ESTABLISHED.*$' -nP flags are optional and UDP is irrelevant for established connections Similar but using the process id: lsof -nP -p PID | egrep -o '(TCP|UDP).*$' Show Sample Output
This is sample output - yours may be different.
```
$ lsof -nP -c apache2 | egrep -o 'TCP.*$' | sort -u
TCP 192.168.0.2:443->192.168.0.136:3373 (ESTABLISHED)
TCP 192.168.0.2:443->192.168.0.137:11127 (ESTABLISHED)
TCP 192.168.0.2:443->192.168.0.137:11153 (ESTABLISHED)
TCP *:443 (LISTEN)
TCP *:80 (LISTEN)

$ lsof -p 17279|egrep -o '(TCP|UDP).*$'
TCP 127.0.0.1:32434 (LISTEN)
UDP *:32435 
```
0

lsof -nP -c COMMAND | egrep -o '(TCP|UDP).*$' | sort -u

forcefsck · 2011-01-25 12:04:13 5

network throughput test

On the machine acting like a server, run: iperf -s On the machine acting like a client, run: iperf -c ip.add.re.ss where ip.add.re.ss is the ip or hostname of the server. Show Sample Output

iperf -s

forcefsck · 2011-01-24 07:58:38 22

String to binary

Cool but useless. Show Sample Output
This is sample output - yours may be different.
```
perl -nle 'printf "%0*v8b\n"," ",$_;'
hello
01101000 01100101 01101100 01101100 01101111
world
01110111 01101111 01110010 01101100 01100100
!
00100001
```
6

perl -nle 'printf "%0*v8b\n"," ",$_;'

forcefsck · 2011-01-21 09:20:54 8
tcptraceroute alternative for udp packets

-T = traceroute -V = verbose --tr-stop = exit when target is reached -n = don't do reverse lookups (faster) -2 = udp -p 53 = destination port 53 (dns), change to your needs Useful when trying to debug a network with complex routing rules and/or multiple gateways.
This is sample output - yours may be different.
0

sudo hping3 -TV --tr-stop -n -2 -p 53 ns1.server.tld

forcefsck · 2011-01-14 10:12:37 4
Generate random valid mac addresses

Shorter and more straightforward. Also in perl: perl -e 'print join(":", map { sprintf "%0.2X",rand(256) }(1..6))."\n"'
This is sample output - yours may be different.
2

for i in {1..6}; do printf "%0.2X:" $[ $RANDOM % 0x100 ]; done | sed 's/:$/\n/'

forcefsck · 2010-12-07 19:26:58 7

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Quickly graph a list of numbers

Useful when you've produced a large file of numbers, and want to quickly see the distribution. The value of y halfway along the x axis is the median. Simple! Just create the listOfNumbers.txt file with a number on each line to try it out.

Find where a kind of file is stored

In this case searches for where .desktop files are stored. The resulted is a sorted list of the top directories containing such files.

Debug redirects between production reloads

Watches the headers of a curl, following any redirects and printing only the HTTP status and the location of the possible redirects.

validate the syntax of a perl-compatible regular expression

Place the regular expression you want to validate between the forward slashes in the eval block.

find established tcp connections without using netstat!!

Fast and easy way to find all established tcp connections without using the netstat command.

Show top committers for SVN repositority for today

Creating ISO Images from CDs/DVDs

create an iso from your cd/dvd-rom device . You need to umount /dev/cdrom before using the cli

move contents of the current directory to the parent directory, then remove current directory.

I think this is less resource consuming than the previous examples

Quickly CD Out Of Directories Without 5+ Aliases

I wrote this a long time ago, wondering why this wasn't floating around somewhere out there (at least not where I could find).. this seems much more simple than multiple aliases and can cd out of directories easier.

External IP (raw data)

can be used in script like : echo $(wget -qO- http://utils.admin-linux.fr/ip.php)

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