Commands by joedhon

Commands by joedhon (10)

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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...
This is sample output - yours may be different.
6

mv {,prefix_}yourfile.txt

joedhon · 2018-08-30 18:18:50 452
Create a bash script from last commands

In order to write bash-scripts, I often do the task manually to see how it works. I type ### at the start of my session. The function fetches the commands from the last occurrence of '###', excluding the function call. You could prefix this with a here-document to have a proper script-header. Delete some lines, add a few variables and a loop, and you're ready to go. This function could probably be much shorter...
This is sample output - yours may be different.
3

quickscript () { filename="$1"; history | cut -c 8- | sed -e '/^###/{h;d};H;$!d;x' | sed '$d' > ${filename:?No filename given} }

joedhon · 2014-02-09 12:19:29 8
tar the current directory wihtout the absolute path

should do the same as command #12875, just shorter.
This is sample output - yours may be different.
-1

tar -cf "../${PWD##*/}.tar" .

joedhon · 2013-11-06 11:15:38 10
Remove all zero size files from current directory (not recursive)
This is sample output - yours may be different.
10

find . -maxdepth 1 -size 0c -delete

joedhon · 2012-04-18 15:01:48 14
annoy your sysadmin colleague

Somehow, i prefer forcing to rm interactively to accidently rm'ing everything...
This is sample output - yours may be different.
-10

cd / && touch ./\-i

joedhon · 2012-04-05 20:55:37 4
Completly blank a disk

Same game as #10096 . loop as many times as you like.
This is sample output - yours may be different.
-5

dd if=/dev/urandom of=/dev/somedisk

joedhon · 2012-01-24 09:13:15 34
return a titlecased version of the string

Needs Bash4. Found at http://stackoverflow.com/questions/2264428/converting-string-to-lower-case-in-bash-shell-scripting alongside a few other tricks.
This is sample output - yours may be different.
1

title() { string=( $@ ); echo ${string[@]^} }

joedhon · 2011-10-14 12:43:45 7
shutdown pc in a 4 hours

you may as well use shutdown -h 18:32 to shutdown your machine at 18:32.
This is sample output - yours may be different.
5

shutdown -h +240

joedhon · 2011-05-02 18:38:57 5
Recursive script to find all epubs in the current dir and subs, then convert to mobi using calibre's ebook-convert utility

-exec sh -c 'var={}; do something with var' lets you do things in a sub-shell while it's faster to type, I'm not sure if dozens of subshells execute quicker than the while loops.
This is sample output - yours may be different.
0

find . -name '*.epub' -exec sh -c 'a={}; ebook-convert $a ${a%.epub}.mobi --still --more --options' \;

joedhon · 2011-04-21 22:03:01 4
Print a row of characters across the terminal

function for .bash_aliases that prints a line of the character of your choice in the color of your choice across the terminal. Default character is "=", default color is white.
This is sample output - yours may be different.
0

println() {echo -n -e "\e[038;05;${2:-255}m";printf "%$(tput cols)s"|sed "s/ /${1:-=}/g"}

joedhon · 2011-01-09 18:08:18 4

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Print a row of 50 hyphens

essentially the ruby one, but perhaps has a larger installed base

Convert seconds to [DD:][HH:]MM:SS

Converts any number of seconds into days, hours, minutes and seconds. sec2dhms() { declare -i SS="$1" D=$(( SS / 86400 )) H=$(( SS % 86400 / 3600 )) M=$(( SS % 3600 / 60 )) S=$(( SS % 60 )) [ "$D" -gt 0 ] && echo -n "${D}:" [ "$H" -gt 0 ] && printf "%02g:" "$H" printf "%02g:%02g\n" "$M" "$S" }

Anti DDOS

Takes IP from web logs and pipes to iptables, use grep to white list IPs.. use if a particular file is getting requested by many different addresses. Sure, its already down pipe and you bandwidth may suffer but that isnt the concern. This one liner saved me from all the traffic hitting the server a second time, reconfigure your system so your system will work like blog-post-1.php or the similar so legitimate users can continue working while the botnet kills itself.

Create a mirror of a local folder, on a remote server

Create a exact mirror of the local folder "/root/files", on remote server 'remote_server' using SSH command (listening on port 22) (all files & folders on destination server/folder will be deleted)

Convert seconds to [DD:][HH:]MM:SS

List of computers not logged into in more than four weeks

I hate `echo X | Y`

apart from not being generalisable to all shells, `Y <<< X` seems nicer to me than `echo X | Y`, e.g. $ <<< lol cat; it reads easier, you type less, and it also looks cool

Slow Down Command Output

( Or $ ls -lat|lolcat -a if you like it in technicolor - apt install lolcat if needed )

exit without saving history

this exits bash without saving the history. unlike explicitly disabling the history in some way, this works anywhere, and it works if you decide *after* issuing the command you don't want logged, that you don't want it logged ... $$ ( or ${$} ) is the pid of the current bash instance this also works perfectly in shells that don't have $$ if you do something like $ kill -9 `readlink /proc/self`

add the result of a command into vi

in command mode, navigate your cursor to the line where you want the command output to appear, and hit "!!". No need to enter edit mode or even type a ":" (colon).

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