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 0
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 1
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 0
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 0

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 1

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 2
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 0
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 0

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Skype conversation logs to IRC-format logs

Convert a flv video file to avi using mencoder

Convert seconds to [DD:][HH:]MM:SS

Converts any number of seconds into days, hours, minutes and seconds. sec2dhms() { declare -i SS="$1" D=$(( SS / 86400 )) H=$(( SS % 86400 / 3600 )) M=$(( SS % 3600 / 60 )) S=$(( SS % 60 )) [ "$D" -gt 0 ] && echo -n "${D}:" [ "$H" -gt 0 ] && printf "%02g:" "$H" printf "%02g:%02g\n" "$M" "$S" }

Remount root in read-write mode.

Saved my day, when my harddrive got stuck in read-only mode.

Find the package that installed a command

Remove a line in a text file. Useful to fix "ssh host key change" warnings

Backup files older than 1 day on /home/dir, gzip them, moving old file to a dated file.

Useful for backing up old files, custom logs, etc. via a cronjob.

Install pip with Proxy

Installs pip packages defining a proxy

Rename files in batch

Perl Command Line Interpreter

Can also just use the debug mode like this.

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