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mysql DB size
This is sample output - yours may be different.
2

mysql -u root -pPasswort -e 'select table_schema,round(sum(data_length+index_length)/1024/1024,4) from information_schema.tables group by table_schema;'

opexxx · 2009-10-06 07:10:49 5
Bashbuiltin printf
This is sample output - yours may be different.
0

cat file.txt | while read line; do printf "%7.2f -> %7.2f\n" $line; done

opexxx · 2009-10-06 07:09:23 7
ffmpeg vhook imlib2.so
This is sample output - yours may be different.
-1

ffmpeg -i input.flv -vhook '/usr/lib/vhook/imlib2.so -c white -x 250 -y H+(-1.8*N+80) -t Hallo! -A max(0,255-exp(N/16))' -sameq -acodec copy output.flv

opexxx · 2009-10-06 07:08:02 3
List open TCP/UDP ports
This is sample output - yours may be different.
2

lsof -i tcp -i udp

raspi · 2009-10-06 02:27:25 8
Print text string vertically, one character per line.
This is sample output - yours may be different.
3

echo "vertical text" | fold -1

zude · 2009-10-05 23:20:14 4
Laminate a file

Consider this file : laminate this file with awk hello to commandlinefu I can use awk substring to laminate words : lamin this file with hello comma Similar to http://www.commandlinefu.com/commands/view/2000/laminate-files-line-by-line Show Sample Output
This is sample output - yours may be different.
```
lamin
this
file
with 
hello
comma
```
-2

awk '{print(substr($0,1,5))}' file

servermanaged · 2009-10-05 18:58:49 4
Generate SHA1 hash for each file in a list

All output is placed in file SHA1SUMS which you can later check with 'sha1sum --check'. Works on most Linux distros where 'sha1sum' is installed.
This is sample output - yours may be different.
2

find . -type f -exec sha1sum {} >> SHA1SUMS \;

gpenguin · 2009-10-05 18:33:59 6
Benchmark report generator

Nicely display in html format a detailed report of the machine, including cpu benchmarks.
This is sample output - yours may be different.
2

hardinfo -am benchmark.so -f html > report.html

servermanaged · 2009-10-05 17:41:25 5
Changing the terminal title to the last shell command

Found another way, more compatible. Tested with xterm, aterm, gnome-terminal and rxvt (where it sets the window title) and guake (where it doesn't - after all, guake does not show the window title).
This is sample output - yours may be different.
0

[[ "x$TERM" == "xrxvt" || "x$XTERM_VERSION" == xXTerm* || "x$COLORTERM" == 'gnome-terminal' && "x$SHELL" == */bin/zsh ]] && preexec () { print -Pn "\e]0;$1\a" }

Patola · 2009-10-05 15:39:45 3
Changing the terminal title to the last shell command

Found the same command for zsh in http://www.davidpashley.com/articles/xterm-titles-with-bash.html - changed it a bit so that the behaviour is the same
This is sample output - yours may be different.
1

if [ "$SHELL" = '/bin/zsh' ]; then case $TERM in rxvt|*term|linux) preexec () { print -Pn "\e]0;$1\a" };; esac; fi

Patola · 2009-10-05 15:21:42 3
Force an fsck on reboot

Force an fsck on reboot. Useful on a system where / has mounted read-only because of file system issues.
This is sample output - yours may be different.
2

shutdown -rF now

SuperFly · 2009-10-05 15:02:36 9
Kill processes that have been running for more than a week
This is sample output - yours may be different.
12

find /proc -user myuser -maxdepth 1 -type d -mtime +7 -exec basename {} \; | xargs kill -9

sharfah · 2009-10-05 14:49:51 9

List open TCP/UDP ports

Works only on Linux. Last option (n) turn name of service resolving (/etc/services) off. Show Sample Output

netstat -ltun

Decoy · 2009-10-05 08:39:03 3

List open TCP/UDP ports
This is sample output - yours may be different.
0

netstat -anp --tcp --udp | grep LISTEN

Crewe · 2009-10-05 08:27:10 4
Get a MySQL DB dump from a remote machine

This command will dump a database on a remote stream to stdout, compress it, stream it to your local machine, decompress it and put it into a file called database.sql.You could even pipe it into mysql on your local machine to restore it immediately. I had to use this recently because the server I needed a backup from didn't have enough disk space.
This is sample output - yours may be different.
8

ssh user@host "mysqldump -h localhost -u mysqluser -pP@$$W3rD databasename | gzip -cf" | gunzip -c > database.sql

daws · 2009-10-05 00:57:51 10
Grep auth log and print ip of attackers

Work for me on CentOS, grep and print ip addresses of ssh bruteforce attempts Show Sample Output
This is sample output - yours may be different.
```
192.33.68.00
192.168.1.66
155.63.49.15
```
1

egrep 'Failed password for invalid' /var/log/secure | awk '{print $13}' | uniq

servermanaged · 2009-10-04 18:08:13 7
Encrypted archive with openssl and tar

The lifehacker way: http://lifehacker.com/software/top/geek-to-live--encrypt-your-data-178005.php#Alternate%20Method:%20OpenSSL "That command will encrypt the unencrypted-data.tar file with the password you choose and output the result to encrypted-data.tar.des3. To unlock the encrypted file, use the following command:" openssl des3 -d -salt -in encrypted-data.tar.des3 -out unencrypted-data.tar Show Sample Output
This is sample output - yours may be different.
```
enter des-ede3-cbc encryption password:
Verifying - enter des-ede3-cbc encryption password:
```
3

openssl des3 -salt -in unencrypted-data.tar -out encrypted-data.tar.des3

berot3 · 2009-10-03 03:50:46 9

Generate SHA1 hash for each file in a list

List files and pass to openssl to calculate the hash for each file. Show Sample Output

ls [FILENAME] | xargs openssl sha1

m00dimus · 2009-10-03 02:05:43 4

On screen display of a command.

This is very useful if you need to show someone some text from a distance. (Like someone standing over your shoulder...) I'd recommend aliasing it to something like: alias osd_cat="osd_cat -o 400 -s 8 -c blue -d 60 -f -*-bitstream\ vera\ sans-*-*-*--200-*-*-*-*-*-*-*" xosd is the utility that provides osd_cat.
This is sample output - yours may be different.
7

date|osd_cat

din7 · 2009-10-02 18:26:46 9
Transfer sqlite3 data to mysql

Filters out all non-insert SQL operations (we couldn't filter out only lines starting with "INSERT" because inserts can span multiple lines), quotes table names with backticks, saves dump to a file and pipes it straight to mysql. This transfers only data--it expects your schema is already in place. In Ruby on Rails, you can easily recreate the schema in MySQL with "rake db:schema:load RAILS_ENV=production".
This is sample output - yours may be different.
0

sqlite3 mydb.sqlite3 '.dump' | grep -vE '^(BEGIN|COMMIT|CREATE|DELETE)|"sqlite_sequence"' | sed -r 's/"([^"]+)"/`\1`/' | tee mydb.sql | mysql -p mydb

mislav · 2009-10-02 14:40:51 4
Verify MD5SUMS but only print failures

All valid files are withheld so only failures show up. No output, all checks good.
This is sample output - yours may be different.
6

md5sum --check MD5SUMS | grep -v ": OK"

gpenguin · 2009-10-02 05:21:17 7
FAST Search and Replace for Strings in all Files in Directory

I needed a way to search all files in a web directory that contained a certain string, and replace that string with another string. In the example, I am searching for "askapache" and replacing that string with "htaccess". I wanted this to happen as a cron job, and it was important that this happened as fast as possible while at the same time not hogging the CPU since the machine is a server. So this script uses the nice command to run the sh shell with the command, which makes the whole thing run with priority 19, meaning it won't hog CPU processing. And the -P5 option to the xargs command means it will run 5 separate grep and sed processes simultaneously, so this is much much faster than running a single grep or sed. You may want to do -P0 which is unlimited if you aren't worried about too many processes or if you don't have to deal with process killers in the bg. Also, the -m1 command to grep means stop grepping this file for matches after the first match, which also saves time. Show Sample Output
This is sample output - yours may be different.
```
Cpu(s): 28.1% us,  9.5% sy,  3.0% ni, 48.6% id,  9.9% wa,  0.2% hi,  0.7% si

  PID NI  %CPU %MEM  COMMAND
20707 19  0.0  0.1   sh -c S=askapache;R=htaccess;find . -type f|xargs -P5 -iFF grep -l -m1 "$S" FF|xargs -P5 -iFF sed -i -e s%${S}%${R}% FF
20708 19  2.0  0.0   find . -type f
20709 19  2.0  0.0   xargs -P5 -iFF grep -l -m1 askapache FF
20710 19  0.5  0.0   xargs -P5 -iFF sed -i -e s%askapache%htaccess% FF
23291 19  0.0  0.0   grep -l -m1 askapache ./servers/util_ldap_cache_mgr.c.html
23293 19  0.0  0.0   grep -l -m1 askapache ./servers/util_md5.c.html
23308 19  0.0  0.0   grep -l -m1 askapache ./servers/waitio.c.html
23310 19  0.0  0.0   grep -l -m1 askapache ./servers/winconfig.h.html
23311 19  0.0  0.0   grep -l -m1 askapache ./servers/wintty.c.html
23265 19  0.0  0.1   sed -i -e s%askapache%htaccess% ./servers/apr_uri.h.html
23266 19  0.0  0.0   sed -i -e s%askapache%htaccess% ./servers/apr_uri.c.html
23267 19  0.0  0.0   sed -i -e s%askapache%htaccess% ./servers/apr_time.h.html
23268 19  0.0  0.0   sed -i -e s%askapache%htaccess% ./servers/apr_user.h.html
23269 19  0.0  0.0   sed -i -e s%askapache%htaccess% ./servers/apr_strmatch.h.html
```
10

sh -c 'S=askapache R=htaccess; find . -mount -type f|xargs -P5 -iFF grep -l -m1 "$S" FF|xargs -P5 -iFF sed -i -e "s%${S}%${R}%g" FF'

AskApache · 2009-10-02 05:03:10 7
generate a unique and secure password for every website that you login to

usage: sitepass MaStErPaSsWoRd example.com description: An admittedly excessive amount of hashing, but this will give you a pretty secure password, It also eliminates repeated characters and deletes itself from your command history. tr '!-~' 'P-~!-O' # this bit is rot47, kinda like rot13 but more nerdy rev # this avoids the first few bytes of gzip payload, and the magic bytes. Show Sample Output
This is sample output - yours may be different.
```
$ sitepass  iHeartLinux commandlinefu.com
^Uk+j{,jl~
```
13

sitepass() { echo -n "$@" | md5sum | sha1sum | sha224sum | sha256sum | sha384sum | sha512sum | gzip - | strings -n 1 | tr -d "[:space:]" | tr -s '[:print:]' | tr '!-~' 'P-~!-O' | rev | cut -b 2-11; history -d $(($HISTCMD-1)); }

grokskookum · 2009-10-01 20:14:57 12
Get length of array in zsh

Returns the index of the last element in the array. Show Sample Output
This is sample output - yours may be different.
```
%foo=(a b c d e)
%echo $foo[(I)$foo[-1]]
5
```
-1

$foo[(I)$foo[-1]]

andrew112358 · 2009-10-01 20:07:14 5
Smart renaming

Use 'mmv' for mass renames. The globbing syntax is intuitive.
This is sample output - yours may be different.
9

mmv 'banana_*_*.asc' 'banana_#2_#1.asc'

hfs · 2009-10-01 13:49:40 4
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check open ports without netstat or lsof

Rename all files which contain the sub-string 'foo', replacing it with 'bar'

That is an alternative to command 8368. Command 8368 is EXTREMELY NOT clever. 1) Will break also for files with spaces AND new lines in them AND for an empty expansion of the glob '*' 2) For making such a simple task it uses two pipes, thus forking. 3) xargs(1) is dangerous (broken) when processing filenames that are not NUL-terminated. 4) ls shows you a representation of files. They are NOT file names (for simple names, they mostly happen to be equivalent). Do NOT try to parse it. Why? see this :http://mywiki.wooledge.org/ParsingLs Recursive version: $ find . -depth -name "*foo*" -exec bash -c 'for f; do base=${f##*/}; mv -- "$f" "${f%/*}/${base//foo/bar}"; done' _ {} +

Converts all pngs in a folder to webp using all available cores

As an alternative to the above command, this one ditches the unnecessary and complicated for loop in favor of a way faster multi-core approach for a task that's more CPU than I/O intensive, making it a perfect suite for GNU parallel

Replace spaces in filename

This command will replace spaces in filename with underscore, for all file in directory that contain spaces.

create dir tree

create tree of dir's in one command

Generate a Random MAC address

Use the following variation for FreeBSD: $ openssl rand 6 | xxd -p | sed 's/$..$/\1:/g; s/:$//'

Download and extract a *tar.gz file with curl.

Check a nfs mountpoint and force a remount if it does not reply after a given timeout.

Based on the execute with timeout command in this site. A more complex script: #!/bin/sh # This script will check the avaliability of a list of NFS mount point, # forcing a remount of those that do not respond in 5 seconds. # # It basically does this: # NFSPATH=/mountpoint TIMEOUT=5; perl -e "alarm $TIMEOUT; exec @ARGV" "test -d $NFSPATH" || (umount -fl $NFSPATH; mount $NFSPATH) # TIMEOUT=5 SCRIPT_NAME=$(basename $0) for i in $@; do echo "Checking $i..." if ! perl -e "alarm $TIMEOUT; exec @ARGV" "test -d $i" > /dev/null 2>&1; then echo "$SCRIPT_NAME: $i is failing with retcode $?."1>&2 echo "$SCRIPT_NAME: Submmiting umount -fl $i" 1>&2 umount -fl $i; echo "$SCRIPT_NAME: Submmiting mount $i" 1>&2 mount $i; fi done

Read info(1) pages using 'less' instead of GNU Texinfo

I like man pages, and I like using `less(1)` as my pager. However, most GNU software keeps the manual in the 'GNU Texinfo' format, and I'm not a fan of the info(1) interface. Just give me less. This command will print out the info(1) pages, using the familiar interface of less!

kill all processes using a directory/file/etc

This command will kill all processes using a directory. It's quick and dirty. One may also use a -9 with kill in case regular kill doesn't work. This is useful if one needs to umount a directory.

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