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commandlinefu.com is the place to record those command-line gems that you return to again and again.

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May 19, 2015 - A Look At The New Commandlinefu
I've put together a short writeup on what kind of newness you can expect from the next iteration of clfu. Check it out here.
March 2, 2015 - New Management
I'm Jon, I'll be maintaining and improving clfu. Thanks to David for building such a great resource!
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awk, bash, curl, find, grep, Linux, sed
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Maintained by Jon H.

Site originally by David Winterbottom (user root).

Psst. Open beta.

Wow, didn't really expect you to read this far down. The latest iteration of the site is in open beta. It's a gentle open beta-- not in prime-time just yet. It's being hosted over at UpGuard (link) and you are more than welcome to give it a shot. Couple things:

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  • » If you wish to use your user account, you will probably need to reset your password.
Your feedback is appreciated via the form on the beta page. Thanks! -Jon & CLFU Team

All commands from sorted by
Terminal - All commands - 12,362 results
find ~/Library/Application\ Support/Firefox/ -type f -name "*.sqlite" -exec sqlite3 {} VACUUM \;
2009-09-02 23:12:13
User: stanishjohnd
Functions: find
Tags: unix firefox optimize sqlite
1
Up
Down
Cleanup firefox's database.

For Mac OS X users only

Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
nmap -R -sL 209.85.229.99/27 | awk '{if($3=="not")print"("$2") no PTR";else print$3" is "$2}' | grep '('
2009-09-02 16:33:15
User: netsaint
Functions: awk grep
Tags: nmap dns
4
Up
Down
List of reverse DNS records for a subnet

This command uses nmap to perform reverse DNS lookups on a subnet. It produces a list of IP addresses with the corresponding PTR record for a given subnet. You can enter the subnet in CDIR notation (i.e. /24 for a Class C)). You could add "--dns-servers x.x.x.x" after the "-sL" if you need the lookups to be performed on a specific DNS server.

On some installations nmap needs sudo I believe. Also I hope awk is standard on most distros.

Show sample output | Comments (1) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
bc -l <<< s(3/5)
2009-09-02 15:41:39
User: akg240
Functions: bc
Tags: bc floating point
3
Up
Down
floating point operations in shell scripts

-l auto-selects many more digits (but you can round/truncate in your head, right) plus it loads a few math functions like sin().

Show sample output | Comments (3) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
awk '/d.[0-9]/{print $4}' /proc/partitions
2009-09-02 15:26:03
User: akg240
Functions: awk
3
Up
Down
list all hd partitions

Only one command and not dependant on full read access to the devices.

Show sample output | Comments (1) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
fdisk -l |grep -e '^/' |awk '{print $1}'|sed -e "s|/dev/||g"
2009-09-02 13:03:04
User: opexxx
Functions: awk fdisk grep sed
0
Up
Down
list all hd partitions
Show sample output | Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
cal -y
2009-09-02 12:57:23
User: andrepuel
Functions: cal
-1
Up
Down
Today's date on a yearly calendar...

Show today date on a yearly calendar.

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free -m | awk '/Swap/ {print $4}'
2009-09-02 11:46:17
User: voyeg3r
Functions: awk free
-2
Up
Down
free swap

simple way to show free swap

Show sample output | Comments (4) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
free -b | grep "Swap:" | sed 's/ * / /g' | cut -d ' ' -f2
2009-09-02 07:16:34
User: opexxx
Functions: cut free grep sed
0
Up
Down
free swap

free swap

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$php_dir/bin/php -i | grep configure
2009-09-02 06:44:12
User: Yousri
Functions: grep
1
Up
Down
to see about php configure

see about php install configure

Show sample output | Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
find ~/.mozilla/firefox/ -type f -name "*.sqlite" -exec sqlite3 {} VACUUM \;
2009-09-01 21:45:46
User: syssyphus
Functions: find
Tags: unix firefox optimize sqlite
18
Up
Down
Cleanup firefox's database.
Comments (4) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
for dnsREC in $(curl -s http://www.iana.org/assignments/dns-parameters |grep -Eo ^[A-Z\.]+\ |sed 's/TYPE//'); do echo -n "$dnsREC " && dig +short $dnsREC IANA.ORG; done
2009-09-01 03:11:18
User: commandlinefu
Functions: dig echo grep sed
-1
Up
Down
dig this
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sudo grub-install --recheck /dev/sda1
2009-09-01 02:06:28
User: theIndianMaiden
Functions: sudo
2
Up
Down
Reinstall Grub
Comments (1) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
grep -lir "sometext" * > sometext_found_in.log
2009-08-31 23:48:45
User: shaiss
Functions: grep
Tags: find text
1
Up
Down
find files containing text

I find this format easier to read if your going through lots of files. This way you can open the file in any editor and easily review the file

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cut -f N- file.dat
2009-08-31 23:08:18
User: sklm
Functions: cut
2
Up
Down
Print all fields in a file/output from field N to the end of the line
Comments (1) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
strace <name of the program>
2009-08-31 20:42:50
User: eitland
Functions: strace
3
Up
Down
Find files that were modified by a given command

Traces the system calls of a program. See http://linuxhelp.blogspot.com/2006/05/strace-very-powerful-troubleshooting.html for more information.

Comments (6) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
awk '{print substr($0, index($0,$N))}'
2009-08-31 19:47:10
User: mstoecker
Functions: awk
0
Up
Down
Print all fields in a file/output from field N to the end of the line

This command will print all fields from the given input to the end of each line, starting with the Nth field.

Comments (1) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
touch /tmp/file ; $EXECUTECOMMAND ; find /path -newer /tmp/file
2009-08-31 18:47:19
User: matthewdavis
Functions: find touch
22
Up
Down
Find files that were modified by a given command

This has helped me numerous times trying to find either log files or tmp files that get created after execution of a command. And really eye opening as to how active a given process really is. Play around with -anewer, -cnewer & -newerXY

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wget -nv http://en.wikipedia.org/wiki/Linux -O- | egrep -o "http://[^[:space:]]*.jpg" | xargs -P 10 -r -n 1 wget -nv
2009-08-31 18:37:33
User: syssyphus
Functions: egrep wget xargs
10
Up
Down
Parallel file downloading with wget

xargs can be used in this manner to download multiple files at a time, and xargs will in this case run 10 processes at a time and initiate a new one when the number running falls below 10.

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dsh -M -c -f servers -- "command HERE"
2009-08-31 12:08:38
User: foob4r
Tags: ssh multiple
4
Up
Down
How to run a command on a list of remote servers read from a file

dsh - Distributed shell, or dancer?s shell ;-)

you can put your servers into /etc/dsh/machines.list than you don't have to serperate them by commata or group them in different files and only run commands for this groups

dsh -M -c -a -- "apt-get update"

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scutil --dns
2009-08-31 10:34:08
User: romant
-1
Up
Down
See the order for DNS resolution on your Mac
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B <<< $(A)
2009-08-30 20:20:18
User: asg0451
6
Up
Down
Who needs pipes?

or: C

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yum --nogpgcheck install "examplePackage"
2009-08-30 18:18:30
User: iDen
Functions: install
-1
Up
Down
Intall not signed packeges with yum

Same as:

1 rpm -ivh package.rpm

2 yum localinstall package.rpm

3 Edit /etc/yum.conf or repository.repo and change the value of gpgcheck from 1 to 0 (!dangerous)

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awk '{print $1}' /var/log/httpd/access_log | sort | uniq -c | sort -rnk1 | head -n 10
2009-08-30 15:32:26
User: flip387
Functions: awk head sort uniq
3
Up
Down
Top 10 requestors by IP address from Apache/NCSA Logs
Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
httpd -S
2009-08-30 15:28:39
User: flip387
-1
Up
Down
Get list of all Apache Virtual Host and which is default for each IP address
Show sample output | Comments (1) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
*/15 * * * * /path/to/command
2009-08-30 14:53:08
User: sharfah
-9
Up
Down
Run a cron job every 15 mins past the hour

Instead of using:

0,15,30,45 * * * * /path/to/command

Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate