Ruby

• show where installed gem through source is:

bundle show spree

• use more cores when running bundle https://coderwall.com/p/xplpua

bundle config --global jobs 4

• uninstall all gems that includes spree in their name

eval $(gem list | grep spree | awk '{ print "gem uninstall " $1}')

• uninstall all gems

for i in `gem list --no-versions`; do gem uninstall -aIx $i; done

• run ruby http server from current directory

ruby -run -e httpd . -p5000

Bash

• find unique lines in file

sort <file> | uniq -c

• find files that matches name and remove them

find . -name "desktop.ini" -exec rm {} \;

• find all files with .rb extension and convert newlines from dos to unix style (CRLF => LF)

find project/path -name '*.rb' -exec dos2unix {} +

DB

• Postgres / MySql search by columns or tables

select * from information_schema.columns
where column_name like '%column_name%'
and table_name like '%table_name%'
and table_schema = 'schema_name';

• MySql find on which table has which indexes: source

SELECT table_name AS `Table`,
       index_name AS `Index`,
       GROUP_CONCAT(column_name ORDER BY seq_in_index) AS `Columns`
FROM information_schema.statistics
WHERE table_schema = 'your_db_name'
GROUP BY 1,2;

Set mysql user's password

mysqladmin -u root password NEWPASSWORD

Allow connections to postgres

sudo vim /etc/postgresql/9.3/main/pg_hba.conf

add a line host all all 192.168.156.1/24 md5 with correct IP.

sudo vim /etc/postgresql/9.3/main/postgresql.conf

Search for listen_address and set it to '*'.

sudo service postgresql restart

Allow connections to MySQL

mysql -uroot -proot
GRANT ALL PRIVILEGES ON *.* TO 'root'@'192.168.56.1' IDENTIFIED BY 'root' WITH GRANT OPTION;
\q

Edit: my.cnf

sudo vim /etc/mysql/my.cnf
# Change `bind-address = 127.0.0.1` to `#bind-address = 127.0.0.1`
sudo service mysql stop
sudo service mysql start

Upgrade Postgres DB

JavaScript

• checkout jquery version

$.fn.jquery

Git

• remove remote branch

git push origin --delete <branchName>

• remove remote tag

git tag -d v1.0.1
git push origin :refs/tags/v1.0.1

• set/check how newline setting is defined for git

git config --global core.autocrlf input

• move recent commits into new branch

git branch newbranch
git reset --hard HEAD~3 # Go back 3 commits. You *will* lose uncommitted work.
git checkout newbranch

System

OS X

• list open ports on machine

sudo lsof -i -P | grep -i "listen"