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Have a list of directories in a file, ending with newlines and need to run du on it?

du only accepts lines ending with a NUL, which can be a pain to create. This solves that issue.
This is sample output - yours may be different.
0

cat filename | tr '\n' '\0' | du -hsc ?files0-from=-

Diluted · 2009-08-21 18:36:49 4
YES = NO
This is sample output - yours may be different.
-3

yes | tr 'y' 'n'

Diluted · 2009-08-21 18:34:52 4
follow the content of all files in a directory

The `-q' arg forces tail to not output the name of the current file
This is sample output - yours may be different.
1

find dir/ -type f | xargs tail -fqn0

chickenzilla · 2009-08-21 18:05:12 4
Download all Phrack .tar.gzs
This is sample output - yours may be different.
7

curl http://www.phrack.org/archives/tgz/phrack[1-67].tar.gz -o phrack#1.tar.gz

amaymon · 2009-08-21 10:14:25 6
Show GCC-generated optimization commands when using the "-march=native" or "-mtune=native" switches for compilation.

You can tell GCC to automatically select optimization commands and produce optimized code for the local machine (the one compiling the code), but you can't normally see what switches have been selected and used unless you append a "-v" and pause compilation. Show Sample Output
This is sample output - yours may be different.
```
This is the output on my AMD Athlon64 X2:

/usr/lib/gcc/i486-linux-gnu/4.3.3/cc1 -E -quiet -v - -D_FORTIFY_SOURCE=2 -march=k8-sse3 -mcx16 -msahf --param l1-cache-size=64 --param l1-cache-line-size=64 -mtune=k8
```
5

cc -march=native -E -v - </dev/null 2>&1 | grep cc1

manny79 · 2009-08-21 09:47:37 11
how long system has been running
This is sample output - yours may be different.
-13

uptime

markoval · 2009-08-21 07:22:21 5
View Processeses like a fu, fu

Shows a less detailed output, made only of the process tree and their pids.
This is sample output - yours may be different.
1

pstree -p

Octave · 2009-08-20 23:31:30 3
Download all Phrack .tar.gzs

This will download all the phracks! Enjoy!
This is sample output - yours may be different.
0

for ((i=1; i<67; i++)) do wget http://www.phrack.org/archives/tgz/phrack${i}.tar.gz -q; done

Abiden · 2009-08-20 23:27:01 6
Not a kismet replacement...

If you're like some individuals who rely on ndiswrapper and cannot use kismet, this command may be of service. watch -n .5 "iwlist wlan0 scan | egrep 'ESSID|Encryption'" Or... watch -n .5 "iwlist wlan0 scan | egrep 'ESSID|Encryption' | egrep 'linksys'" :-) Hopefully you'll find some dd-wrt compatible routers.
This is sample output - yours may be different.
1

watch -n .5 "iwlist wlan0 scan"

Abiden · 2009-08-20 23:05:04 3
clear the cache from memory
This is sample output - yours may be different.
2

sync; echo 3 > /proc/sys/vm/drop_caches

lunarblu · 2009-08-20 17:28:56 7
Visit another command line gōngfu site

Today I learned that commandlinefu.com is not a alone in its conquest for further the knowledge about the command line. Allow me to introduce you to http://shell-fu.org/
This is sample output - yours may be different.
-9

lynx http://shell-fu.org/

penpen · 2009-08-20 11:47:35 5
for all who don't have the watch command
This is sample output - yours may be different.
3

watch() { t=$1; shift; while test :; do clear; date=$(date); echo -e "Every "$t"s: $@ \t\t\t\t $date"; $@; sleep $t; done }

yaccovs · 2009-08-19 19:55:55 3
Schedule a script or command in x num hours, silently run in the background even if logged out

doesn't require "at", change the "2h" to whatever you want... (deafult unit for sleep is seconds)
This is sample output - yours may be different.
25

( ( sleep 2h; your-command your-args ) & )

sitaram · 2009-08-19 17:39:11 12
for all who don't have the watch command

#Usage: watch timeinsecond "command" Show Sample Output
This is sample output - yours may be different.
```
Every 3s: ls 				 Mi 19 Aug 2009 17:27:24 CEST
file1
file2
file3
...
```
4

watch() { while test :; do clear; date=$(date); echo -e "Every "$1"s: $2 \t\t\t\t $date"; $2; sleep $1; done }

peshay · 2009-08-19 15:29:00 3
Save iptables firewall info

Stores the currently active iptables rules to a file that will be applied upon reboot
This is sample output - yours may be different.
-3

sudo iptables-save > /etc/iptables.up.rules

kamiller · 2009-08-19 14:55:05 4
Update iptables firewall with a temp ruleset

If you don't save the rule set it won't be applied during a reboot
This is sample output - yours may be different.
-1

sudo iptables-restore < /etc/iptables.test.rules

kamiller · 2009-08-19 14:38:08 4
Watch mysql processlist on a remote host

Locally watch MySQL process list update every 5s on a remote host. While you watch pipe to a file. The file out put is messy though but hey at least you have a history of what you see.
This is sample output - yours may be different.
-1

watch -n 0.5 ssh [user]@[host] mysqladmin -u [mysql_user] -p[password] processlist | tee -a /to/a/file

lunarblu · 2009-08-19 14:21:27 6
Emptying a text file in one shot in VIM
This is sample output - yours may be different.
-4

:!>test.txt

amaymon · 2009-08-19 13:45:23 4
Emulate sleep in DOS/BAT

Enable 'sleep' function in Windows environment where this does not exist, although not exact in time. (there is a delay for each ping) This is a simple way to separate commands with a time-period. Show Sample Output
This is sample output - yours may be different.
```
sleep() begins: 15:37:49,76
sleep() end: 15:37:49,76
sleep() end: 15:37:49,76
sleep() end: 15:37:49,76
sleep() end: 15:37:49,76
sleep() end: 15:37:49,76
sleep() end: 15:37:49,76
sleep() end: 15:37:49,76
sleep() end: 15:37:49,76
sleep() end: 15:37:49,76
sleep() end: 15:37:49,76
```
-2

echo sleep() begins: %TIME% && FOR /l %a IN (10,-1,1) do (ECHO 1 >NUL %as&ping -n 2 -w 1 127.0.0.1>NUL) && echo sleep() end: %TIME%

pfredrik · 2009-08-19 13:43:09 3
Find UTF-8 text files misinterpreted as ISO 8859-1 due to Byte Order Mark (BOM) of the Unicode Standard.

Character: "?" is the Byte Order Mark (BOM) of the Unicode Standard. Specifically it is the hex bytes EF BB BF, which form the UTF-8 representation of the BOM, misinterpreted as ISO 8859/1 text instead of UTF-8. Show Sample Output
This is sample output - yours may be different.
```
..list of files containing "BOM".
```
4

find . -type f | grep -rl $'\xEF\xBB\xBF'

pfredrik · 2009-08-19 13:27:09 3
Remove CR from Windows- / DOS-textfiles
This is sample output - yours may be different.
0

dos2unix file.txt

sklm · 2009-08-19 13:23:48 3

Remove ^M characters at end of lines in vi

Whereas ^V is CTRL-V. converts a dos file to unix by removing 0x13 characters Show Sample Output

-1

:%s/^V^M//g

slim · 2009-08-19 11:59:22 4

Emptying a text file in one shot

deletes to the end of the buffer Show Sample Output
This is sample output - yours may be different.
```
~
```
-1

ggdG

slim · 2009-08-19 11:40:55 3
Search for an active process without catching the search-process

This does the same thing as many of the 'grep' based alternatives but allows a more finite control over the output. For example if you only wanted the process ID you could change the command: ps -ef | awk '/mingetty/ && !/awk/ {print $2}' If you wanted to kill the returned PID's: ps -ef | awk '/mingetty/ && !/awk/ {print $2}' | xargs -i kill {} Show Sample Output
This is sample output - yours may be different.
```
$ ps -ef | awk '/mingetty/ && !/awk/ {print}'
root      4976     1  0 Jul01 tty1     00:00:00 /sbin/mingetty --noclear tty1
root      4977     1  0 Jul01 tty2     00:00:00 /sbin/mingetty tty2
root      4978     1  0 Jul01 tty3     00:00:00 /sbin/mingetty tty3
root      4979     1  0 Jul01 tty4     00:00:00 /sbin/mingetty tty4
root      4980     1  0 Jul01 tty5     00:00:00 /sbin/mingetty tty5
root      4981     1  0 Jul01 tty6     00:00:00 /sbin/mingetty tty6
```
1

ps -ef | awk '/process-name/ && !/awk/ {print}'

dopeman · 2009-08-19 11:22:09 3
Watch changeable interrupts continuously
This is sample output - yours may be different.
0

watch -n1 'cat /proc/interrupts

theIndianMaiden · 2009-08-19 11:10:55 3
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clean up memory of unnecessary things (Kernerl 2.6.16 or newer)

run sync first to flush useful things out to disk!!! To free pagecache: echo 1 > /proc/sys/vm/drop_caches To free dentries and inodes: echo 2 > /proc/sys/vm/drop_caches To free pagecache, dentries and inodes: echo 3 > /proc/sys/vm/drop_caches

Visualizing system performance data

Determine whether a CPU has 64 bit capability or not

Determine if a command is in your $PATH using POSIX

it is generally advised to avoid using which(1) whenever possible. which(1) is usually a csh(1) script, or sometimes a compiled binary. It's output is highly variable from operating system to operating system, so platform independent scripts could become quite complicated with the logic. On HP-UX 10.20, for example, it prints "no bash in /path /path /path ..."; on OpenBSD 4.1, it prints "bash: Command not found."; on Debian (3.1 through 5.0 at least) and SuSE, it prints nothing at all; on Red Hat 5.2, it prints "which: no bash in (/path:/path:...)"; on Red Hat 6.2, it writes the same message, but on standard error instead of standard output; and on Gentoo, it writes something on stderr. And given all these differences, it's still variable based on your shell. This is why POSIX is king. See http://mywiki.wooledge.org/BashFAQ/081 for more ways on avoiding which(1).

Given process ID print its environment variables

Same as previous but compatible with BSD/IPSO

Stop Flash from tracking everything you do.

Brute force way to block all LSO cookies on a Linux system with the non-free Flash browser plugin. Works just fine for my needs. Enjoy.

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"

Resolve the "all display buffers are busy, please try later" error on a Foundry

list block devices

Shows all block devices in a tree with descruptions of what they are.

Port scan a range of hosts with Netcat.

Simple one-liner for scanning a range of hosts, you can also scan a range of ports with Netcat by ex.: nc -v -n -z -w 1 192.168.0.1 21-443 Useful when Nmap is not available:) Range declaration like X..X "for i in {21..29}" is only works with bash 3.0+

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