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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/
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Commands using echo

Commands using echo from sorted by
Terminal - Commands using echo - 1,101 results
while read l; do echo -e "$l"; done <1.txt >2.txt
2012-03-13 14:27:49
User: knoppix5
Functions: echo read
Tags: bash read
5

Bash only, no sed, no awk. Multiple spaces/tabs if exists INSIDE the line will be preserved. Empty lines stay intact, except they will be cleaned from spaces and tabs if any available.

step3() { s=$(echo -n $b | openssl dgst -sha1 -hmac $hmac -binary | openssl base64); signature=`for((i=0;i<${#s};i++)); do case ${s:i:1} in +) e %2B;; /) e %2F;; =) e %3D;; *) e ${s:i:1};; esac ; done` ; } ; e() { echo -n $1; }
2012-03-11 10:44:01
User: nixnax
Functions: echo
6

This is the THIRD in a set of five commands. See my other commands for the previous two.

This step creates the oauth 1.0 token as explained in http://oauth.net/core/1.0/

The token is required for a Twitter filtered stream feed (and almost all Twitter API calls)

This token is simply an encrypted version of your base string. The encryption key used is your hmac.

The last part of the command scans the Base64 token string for '+', '/', and '=' characters and converts them to percentage-hex escape codes. (URI-escapeing). This is also a good example of where the $() syntax of Bash command substitution fails, while the backtick form ` works - the right parenthesis in the case statement causes a syntax error if you try to use the $() syntax here.

See my previous two commands step1 and step2 to see how the base string variable $b and hmac variable $hmac are generated.

for i in $(seq 1 20); do while read line; do echo "$i: $line"; done<$i.py; done
watch() { while true; do echo "<Ctrl+V><Ctrl+L>Every 2.0s: $@"; date; eval "$@"; sleep 2; done }
2012-03-07 09:30:15
User: hfs
Functions: echo eval sleep watch
Tags: watch
0

Usage:

watch ls -l

Basic but usable replacement for the "watch" command for those systems which don't have it (e.g. the Solaris I'm trapped on).

Type Ctrl+V to escape the following Ctrl+L which clears the screen. It will be displayed as "^L".

for ((x=0;;x+=5)); do sleep 5; hours=$(($x/3600)); minutes=$(($x%3600/60)); seconds=$(($x%60)); echo "$hours hours $minutes minutes $seconds seconds have elapsed" | festival --tts & done
2012-03-06 22:58:43
User: mrklaw
Functions: echo sleep
0

Says time every 5 seconds in hours, minutes and seconds using festival.

for ((x=0;;x+=5)); do sleep 5; echo $x | festival --tts & done
2012-03-06 21:17:51
User: mrklaw
Functions: echo sleep
0

works the same, but uses festival instead of espeak

x=1024; y=32768; cat <(echo -e "P5\n$x $y\n255\n") <(dd if=/dev/sda1 bs=$x count=$y) > sda1.pgm
2012-03-06 03:09:16
Functions: cat dd echo
Tags: dd images pnm pgm
1

Keep width to a power of 2 to see patterns emerge. 512 is good. So is 4096 for huge maps.

PNM headers are super basic.

http://netpbm.sourceforge.net/doc/pbm.html

watch() { if [ -z "$1" ]; then echo "usage: watch interval command" return fi sec=$1 shift while test :; do clear; date=$(date); echo -e "Every "$sec"s: $@ \t\t\t\t $date"; echo $@; sleep $sec; done }
cat z.log | cut -d ':' -f1 | sort | uniq | xargs -l1 -iFF echo 'echo FF $(cat z.log | grep -e "^FF" | grep -e Timeout | wc -l )' | bash
lsof -n -P|grep FlashXX|awk '{ print "/proc/" $2 "/fd/" substr($4, 1, length($4)-1) }'|while read f;do newname=$(exiftool -FileModifyDate -FileType -t -d %Y%m%d%H%M%S $f|cut -f2|tr '\n' '.'|sed 's/\.$//');echo "$f -> $newname";cp $f ~/Vids/$newname;done
2012-02-25 01:49:45
User: mhs
Functions: awk cp cut echo grep read sed tr
8

Certain Flash video players (e.g. Youtube) write their video streams to disk in /tmp/ , but the files are unlinked. i.e. the player creates the file and then immediately deletes the filename (unlinking files in this way makes it hard to find them, and/or ensures their cleanup if the browser or plugin should crash etc.) But as long as the flash plugin's process runs, a file descriptor remains in its /proc/ hierarchy, from which we (and the player) still have access to the file. The method above worked nicely for me when I had 50 tabs open with Youtube videos and didn't want to have to re-download them all with some tool.

die_msg() { echo $@ >&2; exit -1; }
2012-02-24 04:06:04
User: admon
Functions: echo exit
0

Using a standard way to handle error message and return code.

testt(){ o=abcdefghLkprsStuwxOGN;echo $@;for((i=0;i<${#o};i++));do c=${o:$i:1};test -$c $1 && help test | sed "/^ *-$c/!d;1q;s/^[^T]*/-$c /;s/ if/ -/";done; }
2012-02-21 16:54:53
User: AskApache
Functions: echo sed test
1

Applies each file operator using the built-in test.

testt /home/askapache/.sq

/home/askapache/.sq

-a True - file exists.

-d True - file is a directory.

-e True - file exists.

-r True - file is readable by you.

-s True - file exists and is not empty.

-w True - the file is writable by you.

-x True - the file is executable by you.

-O True - the file is effectively owned by you.

-G True - the file is effectively owned by your group.

-N True - the file has been modified since it was last read.

Full Function:

testt ()

{

local dp;

until [ -z "${1:-}" ]; do

dp="$1";

[[ ! -a "$1" ]] && dp="$PWD/$dp";

command ls -w $((${COLUMNS:-80}-20)) -lA --color=tty -d "$dp";

[[ -d "$dp" ]] && find "$dp" -mount -depth -wholename "$dp" -printf '%.5m %10M %#15s %#9u %-9g %#5U %-5G %Am/%Ad/%AY %Cm/%Cd/%CY %Tm/%Td/%TY [%Y] %p\n' -a -quit 2> /dev/null;

for f in a b c d e f g h L k p r s S t u w x O G N;

do

test -$f "$dp" && help test | sed "/-$f F/!d" | sed -e 's#^[\t ]*-\([a-zA-Z]\{1\}\) F[A-Z]*[\t ]* True if#-\1 "'$dp'" #g';

done;

shift;

done

}

cmdfu(){ local t=~/cmdfu;echo -e "\n# $1 {{{1">>$t;curl -s "commandlinefu.com/commands/matching/$1/`echo -n $1|base64`/plaintext"|sed '1,2d;s/^#.*/& {{{2/g'>$t;vim -u /dev/null -c "set ft=sh fdm=marker fdl=1 noswf" -M $t;rm $t; }
2012-02-21 05:43:16
User: AskApache
Functions: echo rm sed vim
5

Here is the full function (got trunctated), which is much better and works for multiple queries.

function cmdfu () {

local t=~/cmdfu;

until [[ -z $1 ]]; do

echo -e "\n# $1 {{{1" >> $t;

curl -s "commandlinefu.com/commands/matching/$1/`echo -n $1|base64`/plaintext" | sed '1,2d;s/^#.*/& {{{2/g' | tee -a $t > $t.c;

sed -i "s/^# $1 {/# $1 - `grep -c '^#' $t.c` {/" $t;

shift;

done;

vim -u /dev/null -c "set ft=sh fdm=marker fdl=1 noswf" -M $t;

rm $t $t.c

}

Searches commandlinefu for single/multiple queries and displays syntax-highlighted, folded, and numbered results in vim.

tail -f file | while read; do echo "$(date +%T.%N) $REPLY"; done
for num in `seq 2 100`;do if [ `factor $num|awk '{print $2}'` == $num ];then echo -n "$num ";fi done;echo
2012-02-18 08:11:19
User: alvinhochun
Functions: awk echo
0

This is actually quite slow~

P.S. change `seq 2 100` to `seq 2 1000` and try

echo -n $(curl -Ss http://icanhazip.com) | xclip
2012-02-17 16:58:40
User: red_five
Functions: echo
0

Gets the IP and sticks it into the middle-mouse-click buffer

ls|grep .mp3 >list.txt; while read line; do newname=`echo $line|sed 's/\ /-/g'|sort`; newname=`echo $newname|tr -s '-' `; echo $newname; echo $newname>> tracklist.txt;mv "$line" "$newname"; done <list.txt; rm list.txt
echo -n '#!'$(which awk)
sayspeed() { for i in $(seq 1 `echo "$1"|wc -c`); do echo -n "`echo $1 |cut -c ${i}`"; sleep 0.1s; done; echo "";}
2012-02-11 05:51:42
User: kundan
Functions: echo seq sleep wc
0

change the time that you would like to have as print interval

and just use it to say whatever you want to

echo -n "IP Address or Machine Name: "; read IP; ping -c 1 -q $IP >/dev/null 2>&1 && echo -e "\e[00;32mOnline\e[00m" || echo -e "\e[00;31mOffline\e[00m"
2012-02-09 07:00:03
User: crlf
Functions: echo ping read
Tags: bash echo IP ping
1

I have used single packet, and in a silent mode with no display of ping stats. This is with color and UI improvement to the http://www.commandlinefu.com/commands/view/10220/check-if-a-machine-is-online. It is as per the enhancements suggested.

ping -c 1 -q MACHINE_IP_OR_NAME >/dev/null 2>&1 && echo ONLINE || echo OFFLINE
2012-02-09 06:30:55
User: UnixNeko
Functions: echo ping
Tags: echo IP ping
8

PING

parameters

c 1 limits to 1 pinging attempt

q makes the command quiet (or silent mode)

/dev/null 2>&1 is to remove the display

&& echo ONLINE is executed if previous command is successful (return value 0)

|| echo OFFLINE is executed otherwise (return value of 1 if unreachable or 2 if you're offline yourself).

I personally use this command as an alias with a predefined machine name but there are at least 2 improvements that may be done.

Asking for the machine name or IP

Escaping the output so that it displays ONLINE in green and OFFLINE in red (for instance).

echo $(date -d @$((0x4f28b47e)))
echo '#!'$(which bash) > script.sh
2012-02-06 08:25:27
User: sharfah
Functions: echo which
Tags: bash
-4

Writes out the shebang line (#!/bin/bash) to the script.

{ echo -n '#!'; which bash; } > script.sh
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%"