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2011-03-12 - Confoo 2011 presentation
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Commands using head from sorted by
Terminal - Commands using head - 216 results
ip a s eth0 | grep "inet " | head -n 1 | awk '{print $2}' | cut -f1 -d'/'
2012-07-16 07:54:43
User: thelan
Functions: awk cut grep head
Tags: IP
-4
Up
Down
Get the IP address

Get the first IPv4 address of an interface

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systemctl --failed | head -n -6 | tail -n -1
2012-07-11 22:31:46
User: corpix
Functions: head tail
0
Up
Down
Print failed units in systemd
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SEED=$(head -1 /dev/urandom|od -N 1);for i in {1..10};do tmp=$(mkpasswd ${RANDOM});pass=${tmp:2:6};echo Pass $pass Crypt: $(mkpasswd $pass);done
2012-07-07 03:20:46
User: dzup
Functions: echo head od
0
Up
Down
Show 10 6 characters pass and crypt(3) *if you like
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find . -type f -print0 | xargs -0 du -h | sort -hr | head -10
2012-06-30 10:03:31
User: netaxiz
Functions: du find head sort xargs
Tags: sort find file size
8
Up
Down
Find biggest 10 files in current and subdirectories and sort by file size
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curl -s kernel.org | grep '<strong>' | head -3 | tail -1 | cut -d'>' -f3 | cut -d'<' -f1
2012-06-15 21:28:42
User: mdix
Functions: cut grep head tail
0
Up
Down
Get current stable kernel version string from kernel.org
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ps -e h -o pid --sort -pcpu | head -10 | vzpid -
2012-05-24 14:16:40
User: mrkmg
Functions: head ps
Tags: openvz
0
Up
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See OpenVZ Container id's of top 10 running processes by %cpu

This command will list the PID, VEID, and Name of the 10 highest cpu using processes on a openvz host. You must have vzpid installed.

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wget -O - http://www.reddit.com/r/wallpapers.rss | grep -Eo 'http://i.imgur.com[^&]+jpg' | head -1 | xargs wget -O background.jpg
2012-04-25 11:15:26
User: untitaker
Functions: grep head wget xargs
0
Up
Down
set desktop background to highest-rated image from Reddit /r/wallpapers

Doesn't depend on curl and doesn't use thumbnails as wallpaper (which has the unfortunate effect of only allowing imgur links)

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(set -o noglob;while sleep 0.05;do for r in `grep -ao '[[:print:]]' /dev/urandom|head -$((COLUMNS/3))`;do [ $((RANDOM%6)) -le 1 ] && r=\ ;echo -ne "\e[$((RANDOM%7/-6+2));32m $r ";done;echo;done)
2012-04-13 02:09:10
User: khopesh
Functions: echo head set sleep
Tags: color screensaver Matrix Matrix Style
0
Up
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Matrix Style

A tweak using Patola's code as a base, this full-width green matrix display has all the frills (and all the printable characters).

You don't need the surrounding parens if you don't care about losing globbing capabilities. Z-shell (/bin/zsh) needs neither the parens nor the `set -o noglob`

Screen shot (animated): http://desmond.imageshack.us/Himg32/scaled.php?server=32&filename=matrixh.gif&res=landing

If it's too slow, try lowering the `sleep 0.05` or even replacing it with `true` (which is faster than `sleep 0`).

I squashed it as narrow as I could to conserve space, though somebody could probably squeeze a char or two out.

Enjoy!

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find . -type f -print0 | xargs -0 du -h | sort -hr | head -20
2012-03-30 10:21:12
User: flatcap
Functions: du find head sort xargs
Tags: sort find du xargs head,
7
Up
Down
Recursively find top 20 largest files (> 1MB) sort human readable format

Search for files and list the 20 largest.

find . -type f

gives us a list of file, recursively, starting from here (.)

-print0 | xargs -0 du -h

separate the names of files with NULL characters, so we're not confused by spaces

then xargs run the du command to find their size (in human-readable form -- 64M not 64123456)

| sort -hr

use sort to arrange the list in size order. sort -h knows that 1M is bigger than 9K

| head -20

finally only select the top twenty out of the list

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head -n1 nation.tbl | sed 's/\(.\)/\1\n/g' | sort | uniq -c | grep \| | awk '{ print $1 }'
2012-03-03 12:35:58
User: maarten
Functions: awk grep head sed sort uniq
0
Up
Down
Count Number of Columns in TPC-H table-file (or any pipe seperated file
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sed -e 's/[;|][[:space:]]*/\n/g' .bash_history | cut --delimiter=' ' --fields=1 | sort | uniq --count | sort --numeric-sort --reverse | head --lines=20
2012-02-17 23:34:16
User: WissenForscher
Functions: cut head sed sort uniq
Tags: bash sort sed uniq
1
Up
Down
Top 20 commands in your bash history
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for i in $(ps -eo pid,pmem,pcpu| sort -k 3 -r|grep -v PID|head -10|awk '{print $1}');do diff -yw <(pidstat -p $i|grep -v Linux) <(ps -o euser,pri,psr,pmem,stat -p $i|tail);done
2012-02-16 20:54:32
User: bob_the_builder
Functions: awk diff grep head ps sort
0
Up
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Displays user-defined ps output and pidstat output about the top CPU or MEMory users.

It grabs the PID's top resource users with $(ps -eo pid,pmem,pcpu| sort -k 3 -r|grep -v PID|head -10)

The sort -k is sorting by the third field which would be CPU. Change this to 2 and it will sort accordingly.

The rest of the command is just using diff to display the output of 2 commands side-by-side (-y flag) I chose some good ones for ps.

pidstat comes with the sysstat package(sar, mpstat, iostat, pidstat) so if you don't have it, you should.

I might should take off the timestamp... :|

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export GREP_COLOR='1;32';while [ true ]; do head -n 100 /dev/urandom; sleep .1; done | hexdump -C | grep --color=auto "ca fe"
2012-02-14 19:30:03
User: tbaschak
Functions: export grep head hexdump sleep true
2
Up
Down
pretend to be busy in office to enjoy a cup of coffee

combination of several of the above

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ls -t1 $* | head -1 ;
2012-02-10 22:13:24
User: darkhorse9933
Functions: head ls
Tags: alias directory files
0
Up
Down
A bash function to show the files most recently modified in the named (or current) directory

Returns the most recently modified file in the current (or specified) directory. You can also get the oldest file, via:

ls -t1 $* | tail-1 ;

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TOTAL_RAM=`free | head -n 2 | tail -n 1 | awk '{ print $2 }'`; PROC_RSS=`ps axo rss,comm | grep [h]ttpd | awk '{ TOTAL += $1 } END { print TOTAL }'`; PROC_PCT=`echo "scale=4; ( $PROC_RSS/$TOTAL_RAM ) * 100" | bc`; echo "RAM Used by HTTP: $PROC_PCT%"
2012-02-03 16:10:36
User: 0disse0
Functions: awk echo grep head tail
Tags: memory usage process
0
Up
Down
display memory usage of a process

page where I got inspiration:

http://www.commandlinefu.com/commands/view/5473/get-acurate-memory-usage-of-a-process-in-megabytes

and

http://www.commandlinefu.com/commands/view/10022/display-the-top-10-running-processes-sorted-by-memory-usage

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while true; do curl -s http://sensiblepassword.com/?harder=1 | tail -n 15 | head -n 1 | sed 's;<br/>;;' | cut -c 5- | cb; sleep 1; done
2012-01-30 20:52:14
User: supervacuo
Functions: cut head sed sleep tail
Tags: copy paste website password clipboard generator generate
1
Up
Down
Generate random sensible passwords, and copy them to the clipboard

Use the excellent sensiblepasswords.com to a generate random (yet easy-to-remember) password every second, and copy it to the clipboard. Useful for generating a list of passwords and pasting them into a spreadsheet.

This script uses "madebynathan"'s "cb" function (http://madebynathan.com/2011/10/04/a-nicer-way-to-use-xclip/); you could also replace "cb" with

xclip -selection c

Remove "while true; do" and "; done" to generate and copy only 1 password.

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PID=`ps | grep process_name | grep -v grep | head -n 1 | awk '{print $1}'`; cat /proc/$PID/smaps | grep heap -A 2
2012-01-30 13:31:40
User: yohananov
Functions: awk cat grep head
Tags: proc
0
Up
Down
Print heap addresses and size
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grep . "$f" | head -n1
2012-01-27 02:58:07
User: captaincomic
Functions: grep head
Tags: grep
0
Up
Down
Get the first non-empty line in a text file

Use this command if your file may contain empty lines and you need to optain the first non-empty line.

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genRandomText() { cat /dev/urandom|tr -dc 'a-zA-Z'|head -c $1 }
2012-01-21 00:51:34
User: thomasba
Functions: cat head tr
Tags: random urandom
0
Up
Down
Generate Random Text based on Length

Using urandom to get random data, deleting non-letters with tr and print the first $1 bytes.

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cat /dev/urandom | tr -dc A-Za-z0-9 | head -c 32
2011-11-20 17:29:45
User: noqqe
Functions: cat head tr
9
Up
Down
Generate a random password 30 characters long
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memnum=$(awk '{ print $2 }' /proc/meminfo |head -n1); echo "$memnum / 1024 / 1024" | bc -l
2011-11-08 16:28:25
User: wekoch
Functions: awk bc echo head
-2
Up
Down
Get memory total from /proc/meminfo in Gigs

Probably more trouble than its worth, but worked for the obscure need.

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ls -ltp | sed '1 d' | head -n1
2011-10-17 16:21:15
User: linuxrawkstar
Functions: head ls sed
-2
Up
Down
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 }
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alias busy='rnd_file=$(find /usr/include -type f -size +5k | sort -R | head -n 1) && vim +$((RANDOM%$(wc -l $rnd_file | cut -f1 -d" "))) $rnd_file'
2011-10-16 00:05:59
User: frntn
Functions: alias cut find head sort vim wc
Tags: bash vim sort find alias cut wc zsh $RANDOM
0
Up
Down
Makes you look busy

Enhancement for the 'busy' command originally posted by busybee : less chars, no escape issue, and most important it exclude small files ( opening a 5 lines file isn't that persuasive I think ;) )

This makes an alias for a command named 'busy'. The 'busy' command opens a random file in /usr/include to a random line with vim.

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tail -n +<N> <file> | head -n 1
2011-09-30 08:30:30
User: qweqq
Functions: head tail
Tags: sed awk tail grep printing print line number
-5
Up
Down
To print a specific line from a file

Tail is much faster than sed, awk because it doesn't check for regular expressions.

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head -n 13 /etc/services | tail -n 1
2011-09-15 19:39:49
User: muonIT
Functions: head tail
Tags: goto
-5
Up
Down
Go to the Nth line of file

Silly approach, but easy to remember...

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