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Grep for a TAB

Grep for a TAB . -- www.fir3net.com --
This is sample output - yours may be different.
-1

grep $'\t' file.txt

felix001 · 2009-10-08 23:14:14 3
SELinux Status

Shows the status of SElinux. -- fir3net.com -- Show Sample Output
This is sample output - yours may be different.
```
[root@linux ~]# getenforce
Disabled
```
-5

getenforce

felix001 · 2009-10-08 23:06:00 5
List only the directories

-d: list directory entries instead of contents, and do not dereference symbolic links
This is sample output - yours may be different.
39

ls -d */

brianmuckian · 2009-10-08 22:07:22 28
Sneaky logout

Remove your BASH history and then link it to /dev/null
This is sample output - yours may be different.
-5

rm ~/.bash_history; ln -s /dev/null ~/.bash_history

unixmonkey6534 · 2009-10-08 17:40:48 14
Using tput to save, clear and restore the terminal contents

Very useful for interactive scripts where you would like to return the terminal contents to its original state before the script was run. This would be similar to how vi exits and returns you to your original terminal screen. Save and clear the terminal contents with: tput smcup Execute some commands, then restore the saved terminal contents with: tput rmcup
This is sample output - yours may be different.
8

tput smcup; echo "Doing some things..."; sleep 2; tput rmcup

jgc · 2009-10-08 16:48:04 24
List only the directories

No need for -l and the output can be sent directly into another function expecting directory names. Show Sample Output
This is sample output - yours may be different.
```
pub/
workspace/
```
-1

ls -F|grep /

romulusnr · 2009-10-08 16:35:15 4
Transforms a file to all uppercase.

same, except it works on any OS with Perl installed. DOS, Windose, whatever
This is sample output - yours may be different.
-2

perl -pi -e 's/([[:lower:]]+)/uc $1/gsex' file

linuxrawkstar · 2009-10-08 14:18:50 3
Sneaky logout
This is sample output - yours may be different.
-7

export HISTFILE=/dev/null && kill -9 $$

ceicke · 2009-10-08 13:02:08 3
Sneaky logout

Best way I know to get rid of .bash_history and don't allow bash to save the current one on exit Edit: added ~/ before .bash_history, just in case... ;)
This is sample output - yours may be different.
-5

rm ~/.bash_history && kill -9 $$

Velenux · 2009-10-08 12:25:47 9
Using column to format a directory listing

Using column to format a directory listing Show Sample Output
This is sample output - yours may be different.
```
PERMISSIONS  LINKS  OWNER  GROUP  SIZE        MONTH  DAY  HH:MM  PROG-NAME
-rw-r--r--   1      root   root   61167       12.    Nov  2008   120253snmp.log
-rw-r--r--   1      root   root   246313      6.     M?r  2008   120_43.log
-rw-r--r--   1      root   root   22947       14.    Mai  09:42  120discovery.log
```
3

(printf "PERMISSIONS LINKS OWNER GROUP SIZE MONTH DAY HH:MM PROG-NAME\n" \ ; ls -l | sed 1d) | column -t

opexxx · 2009-10-08 11:53:38 5
Transforms a file to all uppercase.

Transforms a file to all uppercase.
This is sample output - yours may be different.
6

tr '[:lower:]' '[:upper:]' <"$1"

opexxx · 2009-10-08 11:34:07 3
Outputs a 10-digit random number
This is sample output - yours may be different.
2

head -c4 /dev/urandom | od -N4 -tu4 | sed -ne '1s/.* //p'

opexxx · 2009-10-08 11:27:20 4
Make perl crash

It is not easy to make perl give a segfault, but this does it. This is a known issue but apparently not easy to fix. This is completely useless except for showing people that perl is not bullet-proof. Show Sample Output
This is sample output - yours may be different.
```
Segmentation fault
```
-2

perl -e '$x = []; push @$x, eval { $x = 1; return $x = 1; }'

dstahlke · 2009-10-07 22:42:18 8
View firewall config including devices on linux w/netfilter

I was previously unaware of the -v switch. As a result I never got specifics about which interfaces the allowed or dropped applied to. Thought I'd share the wealth... FYI, -n prevents DNS resolving of IPs.
This is sample output - yours may be different.
0

iptables -L -n -v

gpenguin · 2009-10-07 21:13:59 3
print crontab entries for all the users that actually have a crontab

This is how I list the crontab for all the users on a given system that actually have a crontab. You could wrap it with a function block and place it in your .profile or .bashrc for quick access. There's prolly a simpler way to do this. Discuss. Show Sample Output
This is sample output - yours may be different.
```
--- crontab for user_one ---
0  16 * * * /bin/foo >>/var/log/foo.log 2>&1
42 10 * * * /bin/bar >>/var/log/bar.log 2>&1

--- crontab for user_two ---
*  *  * * * /bin/foo >>/var/log/foo.log 2>&1
16 10 * * * /bin/bar >>/var/log/bar.log 2>&1
```
6

for USER in `cut -d ":" -f1 </etc/passwd`; do crontab -u ${USER} -l 1>/dev/null 2>&1; if [ ! ${?} -ne 0 ]; then echo -en "--- crontab for ${USER} ---\n$(crontab -u ${USER} -l)\n"; fi; done

tharant · 2009-10-07 20:51:01 4
Comment out a line in a file

This will comment out a line, specified by line number, in a given file.
This is sample output - yours may be different.
5

sed -i '19375 s/^/#/' file

BoxingOctopus · 2009-10-07 17:50:40 7
sort lines by length
This is sample output - yours may be different.
6

awk '{print length, $0;}' | sort -nr

ashawley · 2009-10-07 16:32:27 4
Get last changed revision to all eclipse projects in a SVN working copy

Searches for all .project files in current folder and below and uses "svn info" to get the last changed revision. The last sed joins every two lines. Show Sample Output
This is sample output - yours may be different.
```
Project1/foo;123
Project1/bar;321
Project2/foobar;213
```
0

find . -iname ".project"| xargs -I {} dirname {} | LC_ALL=C xargs -I {} svn info {} | grep "Last Changed Rev\|Path" | sed "s/Last Changed Rev: /;/" | sed "s/Path: //" | sed '$!N;s/\n//'

hurz · 2009-10-07 16:13:27 5
More precise BASH debugging
This is sample output - yours may be different.
18

env PS4=' ${BASH_SOURCE}:${LINENO}(${FUNCNAME[0]}) ' sh -x /etc/profile

oernii2 · 2009-10-07 14:44:59 14

Refresh the cache of font directory , usefull after you download font (.ttf or other) from various website and you don't want to reboot or relogin . Close your word processor before using the command , after the refresh reopen your word processor , new fonts is avaible ! Show Sample Output

This is sample output - yours may be different.

gnu@robby:~/.fonts$ sudo fc-cache -f -v
/usr/share/fonts: caching, new cache contents: 0 fonts, 4 dirs
/usr/share/fonts/X11: caching, new cache contents: 0 fonts, 6 dirs
/usr/share/fonts/X11/100dpi: caching, new cache contents: 0 fonts, 0 dirs
/usr/share/fonts/X11/75dpi: caching, new cache contents: 0 fonts, 0 dirs
/usr/share/fonts/X11/Type1: caching, new cache contents: 83 fonts, 0 dirs
/usr/share/fonts/X11/encodings: caching, new cache contents: 0 fonts, 1 dirs
/usr/share/fonts/X11/encodings/large: caching, new cache contents: 0 fonts, 0 dirs
/usr/share/fonts/X11/misc: caching, new cache contents: 0 fonts, 0 dirs
/usr/share/fonts/X11/util: caching, new cache contents: 0 fonts, 0 dirs
/usr/share/fonts/cmap: caching, new cache contents: 0 fonts, 0 dirs
/usr/share/fonts/truetype: caching, new cache contents: 0 fonts, 16 dirs
/usr/share/fonts/truetype/arphic: caching, new cache contents: 12 fonts, 0 dirs
/usr/share/fonts/truetype/freefont: caching, new cache contents: 12 fonts, 0 dirs
/usr/share/fonts/truetype/kochi: caching, new cache contents: 4 fonts, 0 dirs
/usr/share/fonts/truetype/latex-xft-fonts: caching, new cache contents: 7 fonts, 0 dirs
/usr/share/fonts/truetype/openoffice: caching, new cache contents: 1 fonts, 0 dirs
/usr/share/fonts/truetype/thai: caching, new cache contents: 51 fonts, 0 dirs
/usr/share/fonts/truetype/ttf-arabeyes: caching, new cache contents: 39 fonts, 0 dirs
/usr/share/fonts/truetype/ttf-bitstream-vera: caching, new cache contents: 10 fonts, 0 dirs
/usr/share/fonts/truetype/ttf-dejavu: caching, new cache contents: 21 fonts, 0 dirs
/usr/share/fonts/truetype/ttf-indic-fonts-core: caching, new cache contents: 11 fonts, 0 dirs
/usr/share/fonts/truetype/ttf-lao: caching, new cache contents: 1 fonts, 0 dirs
/usr/share/fonts/truetype/ttf-liberation: caching, new cache contents: 12 fonts, 0 dirs
/usr/share/fonts/truetype/ttf-sil-yi: caching, new cache contents: 1 fonts, 0 dirs
/usr/share/fonts/truetype/unfonts: caching, new cache contents: 4 fonts, 0 dirs
/usr/share/fonts/truetype/unifont: caching, new cache contents: 1 fonts, 0 dirs
/usr/share/fonts/truetype/wqy: caching, new cache contents: 1 fonts, 0 dirs
/usr/share/fonts/type1: caching, new cache contents: 0 fonts, 1 dirs
/usr/share/fonts/type1/gsfonts: caching, new cache contents: 35 fonts, 0 dirs
/usr/share/X11/fonts: skipping, no such directory
/usr/local/share/fonts: caching, new cache contents: 0 fonts, 0 dirs
/home/gnu/.fonts: caching, new cache contents: 31 fonts, 0 dirs
/usr/share/texmf/fonts/type1/public/lm: caching, new cache contents: 92 fonts, 0 dirs
/usr/share/fonts/truetype/ttf-malayalam-fonts: skipping, no such directory
/var/cache/fontconfig: cleaning cache directory
/home/gnu/.fontconfig: cleaning cache directory
fc-cache: succeeded

sudo fc-cache -f -v

eastwind · 2009-10-07 11:01:29 8

Enable programmable bash completion in debian lenny

The really awesome bash completion in debian seems to be an extra package now, which has to be installed. After sourcing /etc/bash_completion it completes almost everything (package names in apt... etc) :-) To make this permanent, put something like this in your .bashrc: if [ -f /etc/bash_completion]; then source /etc/bash_completion fi
This is sample output - yours may be different.
3

aptitude install bash-completion ; source /etc/bash_completion

flart · 2009-10-07 09:27:02 6
Convert unix timestamp to date

The "-d" option for gnu's "date" command can calculate positive or negative offset from any time, including "now". You can even specify a source timezone (the output timezone can be set with the TZ environment variable). Useful! Fun! Not very well documented! Show Sample Output
This is sample output - yours may be different.
```
$ date -ud "1970-01-01 + 1234567890 seconds"
Fri Feb 13 23:31:30 UTC 2009

# and back again
$ date -ud "Fri Feb 13 23:31:30 2009" +%s
1234567890
```
6

date -ud "1970-01-01 + 1234567890 seconds"

zude · 2009-10-07 04:35:40 8
Print a list of the 30 last modified mp3s sorted by last first
This is sample output - yours may be different.
2

find ~/Music -daystart -mtime -60 -name *mp3 -printf "%T@\t%p\n" | sort -f -r | head -n 30 | cut -f 2

iadbungler · 2009-10-06 17:57:04 3
List only locally modified files with CVS
This is sample output - yours may be different.
1

cvs -n update 2>null | grep -i "M " | sed s/"M "//

noisy · 2009-10-06 16:03:02 4
Insert a comment on command line for reminder

Comments can be used directly on the command line so I can save in the history a brief description of what command does.
This is sample output - yours may be different.
5

ls -alh #mycomment

servermanaged · 2009-10-06 13:55:06 8
‹ First < 439 440 441 442 443 > Last ›

What's this?

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IP addresses connected to port 80

IP addresses and number of connections connected to port 80.

convert hex to decimal ; decimal to hex

check open ports without netstat or lsof

Find the package that installed a command

Adding Prefix to File name

Good old bracket expansion :-) For large numbers of files, "rename" will spare you the for-loop, or the find/exec...

Convert embedded spaces in filenames to "_" (underscore)

This command converts filenames with embedded spaces in the current directory replacing spaces with the underscore ("_") character.

Get AWS temporary credentials ready to export based on a MFA virtual appliance

You might want to secure your AWS operations requiring to use a MFA token. But then to use API or tools, you need to pass credentials generated with a MFA token. This commands asks you for the MFA code and retrieves these credentials using AWS Cli. To print the exports, you can use: `awk '{ print "export AWS_ACCESS_KEY_ID=\"" $1 "\"\n" "export AWS_SECRET_ACCESS_KEY=\"" $2 "\"\n" "export AWS_SESSION_TOKEN=\"" $3 "\"" }'` You must adapt the command line to include: * $MFA_IDis ARN of the virtual MFA or serial number of the physical one * TTL for the credentials

Averaging columns of numbers

This example calculates the averages of column one and column two of "file.dat". It can be easily modified if other columns are to be averaged.

format txt as table

Backup with versioning

Apart from an exact copy of your recent contents, also keep all earlier versions of files and folders that were modified or deleted. Inspired by EVACopy http://evacopy.sourceforge.net

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