Jay jay-lannister

## delete-files-with-size-0.sh
find . -size 0 -delete

## Asset.sh
# ref: http://osxdaily.com/2014/11/20/flush-dns-cache-mac-os-x/
# Clear MDNS Cache

sudo discoveryutil mdnsflushcache

# Clear UDNS Cache

sudo discoveryutil udnsflushcaches

# Flush and Reset All DNS Caches in OS X Yosemite

## get-top-5-process-by-memory-usage.sh
ps -eF --sort -rss |head -n 5

ps -eo pmem,pcpu,vsize,pid,cmd | sort -k 1 -nr | head -5

ps aux | awk '{print $2, $4, $11}' | sort -k2rn | head -n 5

## prevent-too-many-connections-from-a-single-host.sh
# Reference: http://security.stackexchange.com/questions/42618/how-to-protect-tomcat-7-against-slowloris-attack


# Use firewall rules to prevent too many connections from a single host. This will mitigate run-of-the-mill Denial of Service attacks but not distributed ones (DDoS).

# Here is an example of an iptables command which can be used to limit the number of concurrent connections that can be established to port 80 from a single client host:

iptables -A INPUT -p tcp --syn --dport 80 -m connlimit --connlimit-above 50 -j REJECT

# This would, however, have side-effects if many users were legitimately connecting from a single IP (e.g. mega-proxy), so the number of connections would need to be tuned reasonably - dependant on the traffic expected.

## attach-new-hdd.sh
fdisk -l

# CentOS 6 uses ext4 as a default filesystem
mkfs.ext4 /dev/xvdj

# CentOS 7 uses xfs as a default filesystem
mkfs.xfs /dev/xvdj


vim /etc/fstab

## kill.sh
# http://www.howtogeek.com/howto/ubuntu/kill-a-process-by-process-name-from-ubuntu-command-line/

# http://stackoverflow.com/questions/8594653/killing-all-process-from-command-line
#
# Side note -
#
# kill -9 is overkill (no pun intended) because it prevents the killed process from running cleanup (e.g., atexit() calls, like the difference between exit and _exit). It may or may not be a problem with firefox, but in general consider trying "kill -9" only after plain "kill" fails.


# kill

## Show which processes are listening to which ports.sh
lsof -i | grep LISTEN

## find.sh
# 문자열 "mysql"이 포함된 파일을 폴더 두 군데를 뒤져서 찾는다.
#
# /System/Library/LaunchDaemons/
# /Library/LaunchDaemons/

grep mysql {,/System}/Library/LaunchDaemons/*

## Asset.sql
select @@datadir;

## 0_reuse_code.js
// Use Gists to store code you would like to remember later on
console.log(window); // log the "window" object to the console
	# ref: http://osxdaily.com/2014/11/20/flush-dns-cache-mac-os-x/
	# Clear MDNS Cache

	sudo discoveryutil mdnsflushcache

	# Clear UDNS Cache

	sudo discoveryutil udnsflushcaches

	# Flush and Reset All DNS Caches in OS X Yosemite
	ps -eF --sort -rss \|head -n 5

	ps -eo pmem,pcpu,vsize,pid,cmd \| sort -k 1 -nr \| head -5

	ps aux \| awk '{print $2, $4, $11}' \| sort -k2rn \| head -n 5
	# Reference: http://security.stackexchange.com/questions/42618/how-to-protect-tomcat-7-against-slowloris-attack


	# Use firewall rules to prevent too many connections from a single host. This will mitigate run-of-the-mill Denial of Service attacks but not distributed ones (DDoS).

	# Here is an example of an iptables command which can be used to limit the number of concurrent connections that can be established to port 80 from a single client host:

	iptables -A INPUT -p tcp --syn --dport 80 -m connlimit --connlimit-above 50 -j REJECT

	# This would, however, have side-effects if many users were legitimately connecting from a single IP (e.g. mega-proxy), so the number of connections would need to be tuned reasonably - dependant on the traffic expected.
	fdisk -l

	# CentOS 6 uses ext4 as a default filesystem
	mkfs.ext4 /dev/xvdj

	# CentOS 7 uses xfs as a default filesystem
	mkfs.xfs /dev/xvdj


	vim /etc/fstab
	# http://www.howtogeek.com/howto/ubuntu/kill-a-process-by-process-name-from-ubuntu-command-line/

	# http://stackoverflow.com/questions/8594653/killing-all-process-from-command-line
	#
	# Side note -
	#
	# kill -9 is overkill (no pun intended) because it prevents the killed process from running cleanup (e.g., atexit() calls, like the difference between exit and _exit). It may or may not be a problem with firefox, but in general consider trying "kill -9" only after plain "kill" fails.


	# kill
	# 문자열 "mysql"이 포함된 파일을 폴더 두 군데를 뒤져서 찾는다.
	#
	# /System/Library/LaunchDaemons/
	# /Library/LaunchDaemons/

	grep mysql {,/System}/Library/LaunchDaemons/*
	// Use Gists to store code you would like to remember later on
	console.log(window); // log the "window" object to the console