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Extract all urls from the last firefox sessionstore.js file used.
This is sample output - yours may be different.
-1

sed -e 's/{"url":/\n&/g' ~/.mozilla/firefox/*/sessionstore.js | cut -d\" -f4

cfajohnson · 2009-12-10 04:31:31 4
Change the homepage of Chromium
This is sample output - yours may be different.
-1

change-homepage(){ sed -ri 's|( "homepage": ").*(",)|\1'"$@"'\2|' .config/chromium/Default/Preferences; }

matthewbauer · 2010-04-10 21:21:55 3
Add EC2 pem key to SSH

This command adds your pem key to SSH so that you no longer have to manually specify it when connecting to EC2 instances. # you can do this: ssh ec2-instance.amazonaws.com # instead of this: ssh -i ~/.ssh/KEY_PAIR_NAME.pem ec2-instance.amazonaws.com Show Sample Output
This is sample output - yours may be different.
```
Identity added: /Users/johndoe/.ssh/KEY_PAIR_NAME.pem (/Users/johndoe/.ssh/KEY_PAIR_NAME.pem)
```
-1

ssh-add ~/.ssh/KEY_PAIR_NAME.pem

brockangelo · 2012-11-03 02:59:52 5
Creating rapidly an html menu

This will create rapidly an html menu. You can paste it in you're html page with the middle button(the wheel). I didn't test it in an html with css, but it seems alright. Show Sample Output
This is sample output - yours may be different.
```
<ul>
 <li>menu 1</li>
  <ul>
   <li>item 1</li>
   <li>item 2</li>
   <li>item 3</li>
   <li>item 4</li>
   <li>item 5</li>
  </ul>
</ul>
<ul>
 <li>menu 2</li>
  <ul>
   <li>item 1</li>
   <li>item 2</li>
   <li>item 3</li>
   <li>item 4</li>
   <li>item 5</li>
  </ul>
</ul>
<ul>
 <li>menu 3</li>
  <ul>
   <li>item 1</li>
   <li>item 2</li>
   <li>item 3</li>
   <li>item 4</li>
   <li>item 5</li>
  </ul>
</ul>
<ul>
 <li>menu 4</li>
  <ul>
   <li>item 1</li>
   <li>item 2</li>
   <li>item 3</li>
   <li>item 4</li>
   <li>item 5</li>
  </ul>
</ul>
```
-1

for menu in {1..4}; do echo -e "<ul>\n <li>menu $menu</li>\n <ul>"; for items in {1..5}; do echo " <li>item $items</li>"; if [ $items -eq 5 ];then echo -e " </ul>";fi;done; echo "</ul>";done | xclip

qcjn · 2013-09-22 06:34:32 6
List complete size of directories (do not consider hidden directories)
This is sample output - yours may be different.
-1

du --max-depth=1 | grep -v '\.\/\.'

netkavu · 2010-04-10 22:14:49 3
find names of files ending in *log that have both foo and bar

Uses xargs to call the second grep with the first grep's results as arguments
This is sample output - yours may be different.
-1

grep -l bar *.log | xargs grep -l foo

dlebauer · 2011-01-10 19:54:46 3
Convert DOS newlines (CR/LF) to Unix format

requires the package tofrodos on Debian/Ubuntu: sudo apt-get install tofrodos
This is sample output - yours may be different.
-1

fromdos <file>

jbuitt · 2011-02-14 17:28:53 3
measure answer time of a web service

This uses curl to find out the access times of a web service Show Sample Output
This is sample output - yours may be different.
```
1. 13:54:15: real 0m0.393s
2. 13:54:21: real 0m0.053s
3. 13:54:28: real 0m0.678s
4. 13:54:34: real 0m0.166s
....
40. ...
```
-1

for i in {1..40};do echo -n $i. $(date +%H:%M:%S):\ ; (time curl 'http://ya.ru/' &> /dev/null) 2>&1|grep real;sleep 1;done

AntonyC · 2011-11-11 10:40:38 3
Change all instances of a word in all files in the current directory

This command will replace all instances of 'foo' with 'bar' in all files in the current working directory.
This is sample output - yours may be different.
-1

perl -pi -e 's/foo/bar/g' $(grep -l foo ./*)

dopeman · 2009-03-27 17:18:08 6
Generate a Universally Unique Identifier (UUID)

http://en.wikipedia.org/wiki/Universally_Unique_Identifier http://www.ossp.org/pkg/lib/uuid/ You'll first need to install the uuid package. Available immediately from apt in Ubuntu, Debian, or other myriad Debian variants. You could always compile it from source as well. Show Sample Output
This is sample output - yours may be different.
```
bfcca18a-8857-11de-bdc3-0024e80e2d83
```
-1

uuid

linuxrawkstar · 2009-08-14 14:02:37 7
List complete size of directories (do not consider hidden directories)
This is sample output - yours may be different.
-1

du -sh * | grep -v '\.\/\.'

marcopferreira · 2010-04-10 23:19:46 4
Get Informed by your box that you are awesome ;)

sends notification msg within repeated intervals of time to notify-send ;) Just for fun.
This is sample output - yours may be different.
-1

while $i;do `notify-send -t 200 "You are awesome :)"`;sleep 60; done;

pahnin · 2011-02-14 18:49:38 7
Clear Cached Memory on Ubuntu

"That's it. Not much to see here. The first command writes any cache data that hasn't been written to the disk out to the disk. The second command tells the kernel to drop what's cached. Not much to it. This invalidates the write cache as well as the read cache, which is why we have the sync command first. Supposedly, it is possible to have some cached write data never make it to disk, so use it with caution, and NEVER do it on a production server. You could ... but why take the risk? As long as you are running a post 2.6.16 kernel,..." Source: http://ubuntuforums.org/showpost.php?p=3621283&postcount=1
This is sample output - yours may be different.
-1

sudo sync && sudo echo 3 | sudo tee /proc/sys/vm/drop_caches

StephenJudge · 2012-03-17 08:27:58 14
Useful to check if the disks as of same size or not. Helpful in checking Raid configs
This is sample output - yours may be different.
-1

df | awk '{if ($2!=dspace) print "different"; dspace=$2;}'

adimania · 2013-03-08 12:09:35 14
purge half of files in backup directory

If you have a directory with lot of backups (full backups I mean), when it gets to some size, you could want to empty some space. With this command you'll remove half of the files. The command assumes that your backup files starts with YYYYMMDD or that they go some alphabetical order. Show Sample Output
This is sample output - yours may be different.
```
(nothing, it will remove half of the files)
```
-1

find . | sort | awk 'NR%2==0' | xargs rm $1

sucotronic · 2013-07-11 07:36:18 10
Shuffle mp3 files in current folder (and subfolders) and play them.

Add `-maxdepth 1` to find to exclude subfolders.
This is sample output - yours may be different.
-1

find . -iname "*.mp3" | mpg123 -Z --list -

bjodah · 2013-12-16 14:07:59 9
Change all instances of a word in all files in the current directory and it's sub-directories

This command will replace all instances of 'foo' with 'bar' in all files in the current working directory and any sub-directories.
This is sample output - yours may be different.
-1

perl -pi -e 's/foo/bar/g' $(grep -rl foo ./*)

dopeman · 2009-03-27 17:21:35 10
For finding out if something is listening on a port and if so what the daemon is.
This is sample output - yours may be different.
-1

lsfo -i :[port number]

unixmonkey11400 · 2010-08-17 19:25:37 3
Get your external IP address

Additionally it may give your geolocation if it's known by hostip.info Show Sample Output
This is sample output - yours may be different.
```
ipv4: 188.165.241.33
hostname: ns390090.ovh.net
city: Roubaix
country: FRANCE (FR)
latitude: 50.7
longitude: 3.1667
```
-1

curl http://my-ip.cc/host.txt

samleb · 2011-09-01 00:28:49 3
find all minimum values in file with at least 100 lines
This is sample output - yours may be different.
-1

for ff in directory; do numLines=`wc -l $ff`; numLines=$(echo $numLines | sed 's/ .*//g'); min=$(sort -nrk 1 $ff | tail -1); if [ $numLines -gt 100 ]; then echo $min >> minValues; fi;done;

user1234 · 2013-09-23 04:04:52 7
return external ip

alternative using 'host' Show Sample Output
This is sample output - yours may be different.
```
67.207.139.81
```
-1

host -t a dartsclink.com | sed 's/.*has address //'

dartsclink · 2009-08-14 16:11:18 13
List complete size of directories (do not consider hidden directories)
This is sample output - yours may be different.
-1

du -sh `ls -p | grep /`

sarcilav · 2010-04-11 02:53:51 11

Get your external IP address

XML version. Additionally it may give your geolocation if it's known by hostip.info Show Sample Output

-1

curl http://my-ip.cc/host.xml

samleb · 2011-09-01 00:30:03 3

Keep gz file after uncompressing
This is sample output - yours may be different.
-1

gunzip -c x.txt.gz >x.txt

zluyuer · 2014-10-24 10:00:21 10
display IP addresses with 5 or more unsuccessful login attempts today

display IP's that unsuccessfully attempted to login 5 or more times today may want to filter any trusted IP's and the localhost useful for obtaining a list IP addresses to block on the firewall Show Sample Output
This is sample output - yours may be different.
```
the output is zero or more IP addresses
```
-1

lastb -i | grep "$(date '+%a %b %d')" | awk '{ print $3 }' | sort | uniq -c | awk '{ if ($1 >= 5) print $2; }'

forestb · 2015-11-20 07:19:20 10
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Check if a remote port is up using dnstools.com (i.e. from behind a firewall/proxy)

Shell function; returns 0 if the port is up, 1 otherwise (check $? after executing). First parameter: IP address/hostname Second parameter: port number There is no error checking for the input parameters.

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" }

Make sudo forget password instantly

By default sudo 'remembers' password for a few minutes, so that you do not need to re-enter password for a series of sudo commands that might follow within a short time duration. However, sometime you might want sudo to instantly 'forget' the password. (Next sudo command will need you to reenter the password) Credit: I first learned this while listening to one of the 'tuxradar' podcast.

Get the size of all the directories in current directory (Sorted Human Readable)

as per eightmillion's comment. Simply economical :)

Rename files in batch

grep across a git repo and open matching files in gedit

Convert CSV to JSON

Replace 'csv_file.csv' with your filename.

Fix Ubuntu's Broken Sound Server

Ever since the switch to pulseaudio, Ubuntu users including myself have found themselves with no sound intermittently. To fix this, just use this command and restarts firefox or mplayer or whatever.

summarize a list of IP addresses, verifying IP address and giving counts for each IP found

Working with lists of IP addresses it is sometimes useful to summarize a count of how many times an IP address appears in the file. This example, summarizeIP, uses another function "verifyIP" previously defined in commandlinefu.com to ensure only valid IP addresses get counted. The summary list is presented in count order starting with highest count.

Simple complete system backup excluding files or directories

You can exclude more system folders or individual files which are not necessary for the backup and can be recreated after the restore procedure, like /lost+found, /mnt, /media, /tmp, /usr ... Restoring the above backup procedure is as simple as becoming root and typing: $ tar zxpf backup.tgz -C / You can extract any file or directory out of the backup.tgz file for recovery, for instance, if you have a corrupt or mis-configured fstab file, you could simply issue the command: $ tar zxpf backup.tgz /ect/fstab -C / Other options: v add verbose option to see files processed A far safer solution is to restore the desired files under a different directory, and then compare, move, or update the files to their original locations afterward.

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