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Terminal - All commands - 11,493 results
last | grep -v "^$" | awk '{ print $1 }' | sort -nr | uniq -c
2009-02-18 16:38:59
User: hkyeakley
Functions: awk grep last sort uniq
15

This command takes the output of the 'last' command, removes empty lines, gets just the first field ($USERNAME), sort the $USERNAMES in reverse order and then gives a summary count of unique matches.

perl -pe '$_=reverse;s/\d{3}(?=\d)(?!.*?\.)/$&,/g;$_=reverse'
2009-02-18 16:34:18
User: sil
Functions: perl
2

Insert a comma where necessary when counting large numbers. I needed to separate huge amounts of packets and after 12+ hours of looking in a terminal, I wanted it in readable form.

blockdev --setra 1024 /dev/sdb
2009-02-18 16:27:01
User: starchox
2

(WARN) This will absolutely not work on all systems, unless you're running large, high speed, hardware RAID arrays. For example, systems using Dell PERC 5/i SAS/SATA arrays. If you have a hardware RAID array, try it. It certainly wont hurt.

You may be can test the speed disk with some large file in your system, before and after using this:

time dd if=/tmp/disk.iso of=/dev/null bs=256k

To know the value of block device parameter known as readahead.

blockdev --getra /dev/sdb

And set the a value 1024, 2048, 4096, 8192, and maybe 16384... it really depends on the number of hard disks, their speed, your RAID controller, etc. (see sample)

printf %d 0x`dd if=/dev/urandom bs=1 count=4 2>/dev/null | od -x | awk 'NR==1 {print $2$3}'`
2009-02-18 16:23:09
User: introp
Functions: awk od printf
1

Sometimes, in a shell script, you need a random number bigger than the range of $RANDOM. This will print a random number made of four hex values extracted from /dev/urandom.

svn diff $* | colordiff | less -r
2009-02-18 16:19:08
User: introp
Functions: diff less
2

I put this in a shell script called "svndiff", as it provides a handy decorated "svn diff" output that is colored (which you can't see here) and paged. The -r is required so less doesn't mangle the color codes.

wget -qO - http://infiltrated.net/blacklisted|awk '!/#|[a-z]/&&/./{print "iptables -A INPUT -s "$1" -j DROP"}'
2009-02-18 16:08:23
User: sil
Functions: wget
33

Blacklisted is a compiled list of all known dirty hosts (botnets, spammers, bruteforcers, etc.) which is updated on an hourly basis. This command will get the list and create the rules for you, if you want them automatically blocked, append |sh to the end of the command line. It's a more practical solution to block all and allow in specifics however, there are many who don't or can't do this which is where this script will come in handy. For those using ipfw, a quick fix would be {print "add deny ip from "$1" to any}. Posted in the sample output are the top two entries. Be advised the blacklisted file itself filters out RFC1918 addresses (10.x.x.x, 172.16-31.x.x, 192.168.x.x) however, it is advisable you check/parse the list before you implement the rules

grep -iR find_me ./
2009-02-18 15:38:59
User: lfamorim
Functions: grep
-4

Searching for a String in Multiple Files With Grep

pg_dump -Ft -b -Uusername -hdb.host.com db_name > db.tar
find . -type l ! -exec test -e {} \; -print
2009-02-18 15:34:25
User: Shango1980
Functions: find test
13

Locate broken symlinks in the current directory. Also useful, to remove broken links:

find . -type l ! -exec test -e {} \; -print0 | xargs -0 rm
ffmpeg -i movie.avi -s 320x240 -b 1000k -vcodec wmv2 -ar 44100 -ab 56000 -ac 2 -y movie.wmv
2009-02-18 15:32:13
User: logik
0

I used this to cut down the file size of a 1gb .avi to about 200mb without sacrificing much quality.

dd if=10gb of=/dev/zero bs=1M count=10240
2009-02-18 15:30:29
User: logik
Functions: dd
-1

Test your XFS filesystem and Raptor hard drives for write performance.

dd if=/dev/zero of=10gb bs=1M count=10240
2009-02-18 15:29:38
User: logik
Functions: dd
1

Test your XFS filesystem and Raptor hard drives for write performance.

ls -ad .*
2009-02-18 15:22:39
User: osantana
Functions: ls
-3

List only hidden files (or directories). You also can use:

ls -lad .*
TF=`mktemp` && man -t YOUR_COMMAND >> $TF && gnome-open $TF
2009-02-18 15:18:35
User: furicle
Functions: man
8

Would be better if gnome-open would accept std in

Should be doable in KDE - anyone?

diff <(sort file1.txt) <(sort file2.txt)
2009-02-18 15:17:59
Functions: diff sort
4

Sees if two records differ in their entries, irrespective of order.

vim scp://username@host//path/to/somefile
wget -qO - snubster.com|sed -n '65p'|awk 'gsub(/<span><br>.*/,"")&&1'|perl -p -e 's:myScroller1.addItem\("<span class=atHeaderOrange>::g;s:</span> <span class=snubFontSmall>::g;s:&quot;:":g;s:^:\n:g;s:$:\n:'
2009-02-18 15:05:13
User: sil
Functions: wget
-2

I've got this posted in one of my .bash_profiles for humor whenever I log in.

sudo dmidecode | grep Serial\ Number | head -n1
2009-02-18 14:54:28
User: nlinux
Functions: grep head sudo
14

This will give you the Dell Service tag number associated with your machine. Incredibly useful when you need that number for tech support or downloads.

tar zcf - user | pv /bin/gzip > /tmp/backup.tar.gz
2009-02-18 14:50:45
User: nlinux
Functions: tar
4

This command tar?s up a directory and sends the output to gzip, showing a rate of 223MB/s.

This may require you installing the pv command.

For debian based users out there:

sudo aptitude install pv
/usr/local/bin/OFPW -mode 1
2009-02-18 14:48:31
User: tomslick
0

Sets the Open Firmware to ask for password when selecting a boot volume other then the hd

watch -d "free -mt"
sed 's/\(..\)/\1:/g;s/:$//' mac_address_list
2009-02-18 14:38:37
User: sil
Functions: sed
5

I sometimes have large files of MAC addresses stored in a file, some databases need the information stored with the semicolon (makes for easier programming a device) others don't. I have a barcode to text file scanner which usually butchers MAC addresses so this was the fix> I initially did this in awk ;)

awk '{for(i=10;i>=2;i-=2)$0=substr($0,1,i)":"substr($0,i+1);print}' mac_address_list

find . -type d -exec chmod 0755 {} \;
2009-02-18 14:38:22
User: osantana
Functions: chmod find
-5

WARNING! This command may set an invalid permission under your current directory.

This command will set the 0755 permissions to all directories under your current directory. An alternative version of this command is: find ~/.ssh -type d -exec chmod 0700 {} \;

find . -type f -exec chmod 0644 {} \;
2009-02-18 14:36:39
User: osantana
Functions: chmod find
-7

WARNING! This command may set an invalid permission under your current directory.

This command will set the 0644 permissions to all files under your current directory. An alternative version of this command is: find ~/.ssh -type f -exec chmod 0600 {} \;

find . -name "*.py[co]" -exec rm -f {} \;
2009-02-18 14:32:28
User: osantana
Functions: find rm
3

This command will erase all bytecode versions of Python modules under the current directory.