Connect to MySQL by parsing Rails database.yml

mysql_from_rails_config.sh

#!/bin/bash

usage () {
	echo "Usage:"
	echo -e "\t$0 [options] [dir] [rails env]"
	echo "Options:"
	echo -e "\t-e rails_env"
	echo -e "\t-f yaml_file"
	echo "Inclusion of 'file' option overrides 'dir' arg"
	echo "@arg dir defaults to pwd"
	echo "@arg rails env defaults to 'development'"
	exit 1
}

increment_arg_i () {
	arg_i=$(( $arg_i + 1 ))
}

IFS=$"\n"
args=( $@ )
arg_i=0
while (( $arg_i < ${#args[@]} )); do
	arg=${args[$arg_i]}
	echo -E "$arg_i"
	case "$arg" in
		-e*)
			if [[ "-e" == "$arg" ]]; then
				increment_arg_i;
				renv="${args[$arg_i]}"
			else
				renv="${arg:2}"
			fi;;
		-f*)
			if [[ "-f" == "$arg" ]]; then
				increment_arg_i;
				file="${args[$arg_i]}"
			else
				file="${arg:2}"
			fi;;
		*)
			if [ ! $dir ]; then
				dir="$arg"
			elif [ ! $renv ]; then
				renv="$arg"
			fi;;
	esac
	increment_arg_i
done
[ $dir ]  || dir=`pwd`
[ $renv ] || renv=development
[ $file ] || file="$dir/config/database.yml"
echo "Reading $file for $renv ..."

load_yaml_val () {
	yaml_val=$( echo -e "$yaml_block" | grep -m1 "$1" | cut -d' ' -f4 )
}

# Parse yaml file
start_line=$(grep -n -m1 "$renv" "$file" | cut -d: -f1)
block_len=$(tail -n +"$start_line" "$file" | grep -m1 -n -P '^\s*$' | cut -d: -f1)
yaml_block=$(tail -n +"$start_line" "$file" | head -n "$block_len")
echo -e "yaml_block:\n$yaml_block"
load_yaml_val adapter; adapter=$yaml_val
load_yaml_val username; username=$yaml_val
load_yaml_val password; password=$yaml_val
load_yaml_val host; host=$yaml_val
load_yaml_val port; port=$yaml_val
load_yaml_val database; schema=$yaml_val
[ $host ] || host='127.0.0.1'
[ $port ] || port='3306'
echo adapter "$adapter"
echo username "$username"
echo password "$password"
echo host "$host"
echo port "$port"
echo schema "$schema"

# execute mysql statement
mysql -u"$username" -p"$password" -P"$port" -h"$host" "$schema"