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2011-03-12 - Confoo 2011 presentation
Slides are available from the commandlinefu presentation at Confoo 2011: http://presentations.codeinthehole.com/confoo2011/
2011-01-04 - Moderation now required for new commands
To try and put and end to the spamming, new commands require moderation before they will appear on the site.
2010-12-27 - Apologies for not banning the trolls sooner
Have been away from the interwebs over Christmas. Will be more vigilant henceforth.
2010-09-24 - OAuth and pagination problems fixed
Apologies for the delay in getting Twitter's OAuth supported. Annoying pagination gremlin also fixed.




Commands using awk from sorted by
Terminal - Commands using awk - 1,150 results
IPADDR=`ifconfig eth0 | grep -i inet | awk -F: '{print $2}'| awk '{print $1}'`
2009-02-25 22:58:19
User: rockon
Functions: awk grep

Useful in scripts while you just need an IP address in a variable.

du --max-depth=1 | sort -r -n | awk '{split("k m g",v); s=1; while($1>1024){$1/=1024; s++} print int($1)" "v[s]"\t"$2}'
2009-02-24 11:03:08
User: hans
Functions: awk du sort

I use this on debian testing, works like the other sorted du variants, but i like small numbers and suffixes :)

for x in `psql -e\l | awk '{print $1}'| egrep -v "(^List|^Name|\-\-\-\-\-|^\()"`; do pg_dump -C $x | gzip > /var/lib/pgsql/backups/$x-nightly.dmp.gz; done
2009-02-21 15:21:09
User: f4nt
Functions: awk egrep gzip

Ran as the postgres user, dumps each database individually. It dumps with the create statements as well, so you can just 'zcat $x-nightly.dmp.gz | psql' to reimport/recreate a database from a backup.

N="filepath" ; P=/proc/$(lsof +L1 | grep "$N" | awk '{print $2}')/fd ; ls -l $P | sed -rn "/$N/s/.*([0-9]+) ->.*/\1/p" | xargs -I_ cat $P/_ > "$N"
2009-02-21 02:31:24
User: laburu
Functions: awk cat grep ls sed xargs

Note that the file at the given path will have the contents of the (still) deleted file, but it is a new file with a new node number; in other words, this restores the data, but it does not actually "undelete" the old file.

I posted a function declaration encapsulating this functionality to http://www.reddit.com/r/programming/comments/7yx6f/how_to_undelete_any_open_deleted_file_in_linux/c07sqwe (please excuse the crap formatting).

for i in `ps aux | grep ssh | grep -v grep | awk {'print $2'}` ; do kill $i; done
ps auxwww | grep outofcontrolprocess | awk '{print $9}' | xargs kill -9
ps aux | awk '/name/ {print $2}'
2009-02-20 21:35:52
User: evil_otto
Functions: awk ps

This finds a process id by name, but without the extra grep that you usually see. Remember, awk can grep too!

top -b -n 1 | awk '{if (NR <=7) print; else if ($8 == "D") {print; count++} } END {print "Total status D: "count}'
lsof | awk '{print $1}' | sort | uniq -c | sort -rn | head
ps aux | grep -i firefox | grep -v grep | awk '{print $2}' | xargs -t -i kill -9 {}
2009-02-19 18:50:00
User: blackdude
Functions: awk grep kill ps xargs

This is a nice way to kill processes.. the example here is for firefox!!! substitute firefox for whatever the process name is...

lsof -p $(netstat -ltpn|awk '$4 ~ /:80$/ {print substr($7,1,index($7,"/")-1)}')| awk '$9 ~ /access.log$/ {print $9| "sort -u"}'
2009-02-19 16:11:54
User: rjamestaylor
Functions: awk netstat

Ever logged into a *nix box and needed to know which webserver is running and where all the current access_log files are? Run this one liner to find out. Works for Apache or Lighttpd as long as CustomLog name is somewhat standard. HINT: works great as input into for loop, like this:

for i in `lsof -p $(netstat -ltpn|awk '$4 ~ /:80$/ {print substr($7,1,index($7,"/")-1)}')| awk '$9 ~ /access.log$/ {print $9| "sort -u"}'` ; do echo $i; done

Very useful for triage on unfamiliar servers!

svn st | grep ^\? | awk '{print $2}' | xargs svn add
netstat -alpn | grep :80 | awk '{print $4}' |awk -F: '{print $(NF-1)}' |sort | uniq -c | sort -n
du -sk * | awk '{print $1} END {print "[+z1<y]sy\nlyx\np"}' | dc
last | grep -v "^$" | awk '{ print $1 }' | sort -nr | uniq -c
2009-02-18 16:38:59
User: hkyeakley
Functions: awk grep last sort uniq

This command takes the output of the 'last' command, removes empty lines, gets just the first field ($USERNAME), sort the $USERNAMES in reverse order and then gives a summary count of unique matches.

printf %d 0x`dd if=/dev/urandom bs=1 count=4 2>/dev/null | od -x | awk 'NR==1 {print $2$3}'`
2009-02-18 16:23:09
User: introp
Functions: awk od printf

Sometimes, in a shell script, you need a random number bigger than the range of $RANDOM. This will print a random number made of four hex values extracted from /dev/urandom.

ps -ef | grep $USERNAME | awk {'print $2'} | xargs kill [-9]
2009-02-17 20:35:35
User: TheNomad
Functions: awk grep kill ps xargs

This is a 'killall' command equivalent where it is not available.

Prior to executing it, set the environment variable USERNAME to the username, whose processes you want to kill or replace the username with the $USERNAME on the command above.

Side effect: If any processes from other users, are running with a parameter of $USERNAME, they will be killed as well (assuming you are running this as root user)

[-9] in square brackets at the end of the command is optional and strongly suggested to be your last resort. I do not like to use it as the killed process leaves a lot of mess behind.

find . -size +10240k -exec ls -l {} \; | awk '{ print $5,"",$9 }'|sort -rn > message.out
2009-02-17 19:39:56
User: rommelsharma
Functions: awk find ls

This command specifies the size in Kilobytes using 'k' in the -size +(N)k option. The plus sign says greater than. -exec [cmd] {} \; invokes ls -l command on each file and awk strips off the values of the 5th (size) and the 9th (filename) column from the ls -l output to display. Sort is done in reversed order (descending) numerically using sort -rn options.

A cron job could be run to execute a script like this and alert the users if a dir has files exceeding certain size, and provide file details as well.

history | awk '{print $2}' | sort | uniq -c | sort -rn | head
awk -F'^"|", "|"$' '{ print $2,$3,$4 }' file.csv
2009-02-16 21:32:46
User: SiegeX
Functions: awk

The $2, $3, $4 fields are arbitrary but note that the first field starts from $2 and the last field is $NF-1. This is due to the fact that the leading and trailing quotes are treated as field delimiters.

newhostname=$(hostname | awk -F. '{print $1 "." $2}'); ipaddress=$(nslookup `hostname` | grep -i address | awk -F" " '{print $2}' | awk -F. '{print $3 "." $4}' | grep -v 64.142);PS1="[`id -un`.$newhostname.$ipaddress]"' (${PWD}): '; export PS1
2009-02-16 20:11:53
User: simardd

changes the PS1 to something better than default.

[username.hostname.last-2-digits-of-ip] (current directory)

find path/to/folder/ -type f -print0 | xargs -0 -n 1 md5sum | awk '{print $1}' | sort | md5sum | awk '{print $1}'
2009-02-16 19:39:37
User: mcover
Functions: awk find md5sum sort xargs

For quick validation of folder's file-contents (structure not taken into account) - I use it mostly to check if two folders' contents are the same.

df / | awk '{print $1}' | grep dev | xargs tune2fs -l | grep create
2009-02-16 18:45:03
User: Kaio
Functions: awk df grep tune2fs xargs

Very useful set of commands to know when your file system was created.

ip route | grep default | awk '{print $3}'
2009-02-16 16:29:03
User: ruedu
Functions: awk grep route

This gets you your default route programatically, useful for scripts

netstat -ntu | awk '{print $5}' | cut -d: -f1 | sort | uniq -c | sort -n | tail
2009-02-16 15:48:27
User: TuxOtaku
Functions: awk cut netstat sort uniq

This command does a tally of concurrent active connections from single IPs and prints out those IPs that have the most active concurrent connections. VERY useful in determining the source of a DoS or DDoS attack.