sergeiwaigant

Semantic Commit Messages

See how a minor change to your commit message style can make you a better programmer.

Format: <type>(<scope>): <subject>

<scope> is optional

Example

sergeiwaigant

Table of Contents

• set -e, -u, -x, -o pipefail
• set -e
• set -x
• set -u
• set -o pipefail
• Setting IFS
• Original Reference

set -e, -u, -x, -o pipefail

sergeiwaigant

sudo iptables -A PREROUTING -t nat -i eth0 -p tcp --dport 80 -j REDIRECT --to-port 8080
sudo iptables -A PREROUTING -t nat -i eth0 -p tcp --dport 443 -j REDIRECT --to-port 8443
sudo sh -c "iptables-save > /etc/iptables.rules"
sudo apt-get install  iptables-persistent

#allows localhost traffic to connect to 443 from 8443
sudo iptables -t nat -A OUTPUT -o lo -p tcp --dport 443 -j REDIRECT --to-port 8443

sergeiwaigant

OpenSSL 🔐

Install

Install the OpenSSL on Debian based systems

sudo apt-get install openssl

sergeiwaigant

Reference https://stackoverflow.com/a/34407620/13287790

$ printf %s 'encode this'|jq -sRr @uri
encode%20this

$ jq -rn --arg x 'encode this' '$x|@uri'
encode%20this

# -r (--raw-output) outputs the raw contents of strings instead of JSON string literals. -n (--null-input) doesn't read input from STDIN.

sergeiwaigant

# Sometimes after a sprint, all the remaining branches are just taking up space.
# Here's a small snippet to remove all your local branches in one go.

git branch | grep -v "master" | xargs git branch -D 

sergeiwaigant

function bashLogger() {
  local logLevel="INFO"
  local logMessage=""

  [[ $# -ge 1 ]] && { logMessage=$1;shift;}
  [[ $# -ge 1 ]] && { logLevel=${logMessage}; logMessage=$1; shift;}

  local additionalMessages="$@"
  local timestamp=$(TZ=UTC-1 date +'%Y-%m-%d %H:%M:%S,%3N')

sergeiwaigant

Here are several different ways to test a TCP port without telnet.

Source: https://gist.github.com/Khoulaiz/41b387883a208d6e914b

BASH (man page)

$ cat < /dev/tcp/127.0.0.1/22
SSH-2.0-OpenSSH_5.3
^C

sergeiwaigant

# Remove all untagged images
docker rmi $(docker images | grep "^<none>" | awk '{print $3}')

# 
docker container prune

# clean up all "Exited" containers
docker rm $(docker ps -a | grep Exited | awk '{ print $1 }')

sergeiwaigant

# Lists one line per Java environment installed (and known to the /usr/bin/java command).
# You can still have e.g. Zulu installations which are not registered
/usr/libexec/java_home -V