Commands using head sorted by votes

Commands using head (314)

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20char long alpahnumeric "password"

20characters long alpahnumeric "password" Show Sample Output
This is sample output - yours may be different.
```
5698d846bfe078d67aef43fc0eebe4233401ad23
```
-1

head -c20 /dev/urandom | xxd -ps

opexxx · 2013-07-16 10:14:21 8
Get current stable kernel version string from kernel.org

Fetches latest stable release version from first entry between tags Show Sample Output
This is sample output - yours may be different.
```
3.12.5
```
-1

curl -s -k https://www.kernel.org/feeds/kdist.xml | sed -n -e 's@.*<guid>$.*$</guid>.*@\1@p' | grep 'stable' | head -1 | awk -F , '{print $3}'

Wafelijzer · 2013-12-17 23:59:27 7
Parse logs for IP addresses and how many hits from each IP
This is sample output - yours may be different.
-1

cat "log" | grep "text to grep" | awk '{print $1}' | sort -n | uniq -c | sort -rn | head -n 100

jmorganwalker · 2014-07-08 15:07:24 10
get line#1000 from text.
This is sample output - yours may be different.
-2

head -1000 < lines.txt | tail -1

wbx · 2009-02-08 06:41:20 15
Creates a random passwort from /dev/urandom [0-9A-za-z]

Replace < pw-length > with the desired password-length. The password-length is not always correct, but wayne...
This is sample output - yours may be different.
-2

head -c $((<pw-lenght>-2)) /dev/urandom | uuencode -m - | sed -e '1d' -e '3d' | sed -e 's/=.*$//g'

P17 · 2009-03-24 20:05:16 9
gzip vs bzip2 at compressing random strings?

Does that count as a win for bzip2? Show Sample Output
This is sample output - yours may be different.
```
$ \ls -l out*
-rw-r--r-- 1 chillu users 789711 2009-04-04 19:01 out.bz
-rw-r--r-- 1 chillu users 789947 2009-04-04 19:01 out.gz
```
-2

< /dev/urandom tr -dc A-Za-z0-9_ | head -c $((1024 * 1024)) | tee >(gzip -c > out.gz) >(bzip2 -c > out.bz) > /dev/null

jnash · 2009-04-04 13:23:01 11
Find the svn directory that a commit was made in. Usefull if you have many projects in one repository.
This is sample output - yours may be different.
-2

echo "12345,12346" |sed -e's/ //'|tr "," "\n"| while read line; do echo -n $line" "; svn log -vr $line https://url/to/svn/repository/|grep "/"|head -1|cut -d"/" -f2; done

psytek · 2009-04-15 15:21:20 4
print random commandlinefu.com submission

ok I'm sure it's not pretty Show Sample Output
This is sample output - yours may be different.
```
Terminal - runs a bash script in debugging mode    
bash -x ./post_to_commandlinefu.sh
```
-2

lynx -source http://www.commandlinefu.com/commands/random | sed 's/<[^>]*>//g' | head -1037 | tail -10 | sed -e 's/^[ \t]*//' | sed '/^$/d' | head -2

lxtips · 2009-06-02 09:48:59 11
Get name of first configured interface

Get the line containing "inet addr:" and the line before that, get down to only the first line, and then get the first word on that line, which should be the interface. Show Sample Output
This is sample output - yours may be different.
```
eth0
```
-2

ifconfig | grep -B 1 "inet addr:" | head -1 | cut -d" " -f1

jasonwalsh · 2010-01-04 23:02:57 5
List top ten files/directories sorted by size

If a directory name contains space xargs will do the wrong thing. Parallel https://savannah.nongnu.org/projects/parallel/ deals better with that. Show Sample Output
This is sample output - yours may be different.
```
33M     a b
17M     libxnee
3.6M    doc
3.0M    gnee
```
-2

du -s * | sort -nr | head | cut -f2 | parallel -k du -sh

unixmonkey8046 · 2010-01-28 12:59:14 6
Find MAC address of Active Eth connection
This is sample output - yours may be different.
-2

/sbin/ifconfig|grep -B 1 inet |head -1 | awk '{print $5}'

octopus · 2010-04-22 06:35:29 6
Set background image to random file from current dir.
This is sample output - yours may be different.
-2

feh --bg-center `ls -U1 |sort -R |head -1`

unixmonkey11903 · 2010-09-06 12:35:35 3
get a list of top 1000 sites from alexa

this will dump a list of domains one per line into a text file
This is sample output - yours may be different.
-2

curl -s -O http://s3.amazonaws.com/alexa-static/top-1m.csv.zip ; unzip -q -o top-1m.csv.zip top-1m.csv ; head -1000 top-1m.csv | cut -d, -f2 | cut -d/ -f1 > topsites.txt

chrismccoy · 2010-11-01 01:25:53 4
get newest file in current directory
This is sample output - yours may be different.
-2

ls -t1 | head -n1

altern · 2011-05-27 09:49:30 5
Grep with one result at a time

Not perfect but working (at least on the project i wrote it ;) ) Specify what you want search in var search, then it grep the folder and show one result at a time. Press enter and then it will show the next result. It can work bad on result in the firsts lines, and it can be improved to allow to come back. But in my case (a large project, i was checking if a value wasn't used withouth is corresponding const and the value is "1000" so there was a lot of result ...) it was perfect ;)
This is sample output - yours may be different.
-2

search="whatyouwant";data=$(grep "$search" * -R --exclude-dir=.svn -B2 -A2);for((i=$(echo "$data" | wc -l);$i>0;i=$(($i-6)) )); do clear;echo "$data"| tail -n $i | head -n 5; read;done

Juluan · 2011-08-29 18:14:16 4
Show the single most recently modified item in a directory

wrap it in a function if you like... lastfile () { ls -ltp | sed '1 d' | head -n1 } Show Sample Output
This is sample output - yours may be different.
```
-rw-r--r--    1 root     root           118 Dec 31  1969 default.prop
```
-2

ls -ltp | sed '1 d' | head -n1

linuxrawkstar · 2011-10-17 16:21:15 7
Get memory total from /proc/meminfo in Gigs

Probably more trouble than its worth, but worked for the obscure need.
This is sample output - yours may be different.
-2

memnum=$(awk '{ print $2 }' /proc/meminfo |head -n1); echo "$memnum / 1024 / 1024" | bc -l

wekoch · 2011-11-08 16:28:25 3
Multiline read

Reads n lines from stdin and puts the contents in a variable. Yes, I know the read command and its options, but find this logical even for one line. Show Sample Output
This is sample output - yours may be different.
```
$ A=$(head -3)
Line1
line2
line3

$ echo "$A"
Line1
line2
line3
```
-2

VAR=$(head -5)

rodolfoap · 2014-04-05 13:45:18 7
Generrate Cryptographically Secure RANDOM PASSWORD

Change :alnum: to :graph: for all printable characters Show Sample Output
This is sample output - yours may be different.
```
FH170AB1DXb4dHlX
```
-2

cat /dev/urandom |tr -c -d '[:alnum:]'|head -c 16;echo

AndrewM · 2019-06-17 17:51:04 36
Delete tens of thousans of files at one go

Deletes thousands of files at one go, I'm not able to recall the exact # of files that rm can delete at one go(apprx. around 7000.)
This is sample output - yours may be different.
-3

rm -rf `ls | head -5000`

rockon · 2009-02-25 22:52:23 7
Random password generating function

This uses urandom to produce a random password. The random values are uuencoded to ensure only printable characters. This only works for a number of characters between 1 and 60. Show Sample Output
This is sample output - yours may be different.
```
$ mkpasswd 56
AB:C[)\"=H#J:E()EY>HA6J,R741+ACL&08PC)P4Z#3R^YZ*3L0@O<<6
$ mkpasswd 9
YMO;<&.FB
```
-3

mkpasswd() { head -c $(($1)) /dev/urandom | uuencode - | sed -n 's/.//;2s/$.\{'$1'\}$.*/\1/p' ;}

taliver · 2009-11-19 14:27:52 5
Echo several blank lines
This is sample output - yours may be different.
-3

yes '' | head -n100

John_W · 2010-09-08 14:59:34 4
Selecting a random file/folder of a folder
This is sample output - yours may be different.
-3

echo Selected $(ls -1 | sort -R | head -n 1)

Juluan · 2011-03-13 22:06:54 3
open the last folder created
This is sample output - yours may be different.
-3

cd $(ls -1t --color=never | head -1)

tchepo · 2011-06-29 15:23:50 3
Cut a large wordlist into smaller chunks

Useful for situations where you have word lists or dictionaries that range from hundreds of megabytes to several gigabytes in size. Replace file.lst with your wordlist, replace 50000 with however many lines you want the resulting list to be in total. The result will be redirected to output.txt in the current working directory. It may be helpful to run wc -l file.lst to find out how many lines the word list is first, then divide that in half to figure out what value to put for the head -n part of the command.
This is sample output - yours may be different.
-3

less file.lst | head -n 50000 > output.txt

Richie086 · 2011-09-05 05:26:04 8
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Check ps output to see if file is running, if not start it

This comes in handy if you have daemons/programs that have potential issues and stop/disappear, etc., can be run in cron to ensure that a program remains up no matter what. Be advised though, if a program did core out, you'd likely want to know why (gdb) so use with caution on production machines.

tree command limit depth for recusive directory list

sometimes I need list from path with max limit for recursive depth directory listing

Perl oneliner to print access rights in octal format

This prints file access rights in octal - useful when "stat" is unavailable.

Query Wikipedia via console over DNS

Shorter version, works with multiple words.

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" }

Duplicating service runlevel configurations from one server to another.

And then to complete the task: Go to target host; $ssh host Turn everything off: $for i in `chkconfig --list | fgrep :on | awk '{print $1}'` ; do chkconfig --level 12345 $i off; done Create duplicate config: $while read line; do chkconfig --level $line on; done < foo

Redirect STDIN

Several times, I find myself hitting my up arrow, and changing the search term. Unfortunately, I find myself wasting too much time typing: $ grep kernel /var/log/messages Redirecting STDIN allows me to put the search term at the end so I less cursor movement to change what I'm searching for: $ < /var/log/messages grep kernel If you're using the emacs keyboard binding, then after you press your up arrow, press CTRL+w to erase the word. If this has already been submitted, I couldn't find it with the search utility.

Which processes are listening on a specific port (e.g. port 80)

swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

Determine whether a CPU has 64 bit capability or not

Check if you have 64bit by looking for "lm" in cpuinfo. lm stands for "long mem". This can also be used without being root.

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

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Commands using head (314)

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