generate a bash alias for each (exact) host line from .ssh/config

ssh_aliases.sh

#!/bin/bash 

##
## create an alias for each unambigous host entry in ${HOME}/.ssh/config
##
## instead of using "ssh myhostname" you can simply use "myhostname" to
## establish a ssh-connection to the host!
##
## You most likely have to change CACHE_FN to point somewhere, 
## where you want to store the cache 
##
## Usage: 
## $ source ssh_aliases.sh
##
##
## Author: Markus Meissner <coder@safemailbox.de>
## LICENSE: Apache License
##


#
# CONFIGURE THESE:
#
CACHE_FN="${HOME}/.bashrc.d/.cache_ssh_aliases.sh"
SSH_BINARY="/usr/bin/ssh"
SSH_CONFIG_FN="${HOME}/.ssh/config"

function __collect_ssh_aliases {
	read_entry=0

	alias_name=""
	target_port=""
	target_host=""
	target_user=""

	OLDIFS=$IFS; 
	IFS=$'\n';

	for line in `cat ${SSH_CONFIG_FN}`; do
		## ignore hosts with wildcards ?/* 
		## and dots (foo.bar)
		if expr match "${line}" 'host' > /dev/null 2>&1; then
			# first write old, if available
			if [[ "$alias_name" != "" ]]; then
				echo "alias ${alias_name}=\"${SSH_BINARY} ${target_port} ${target_user}${target_host}\"" >> ${CACHE_FN}
				alias_name=""
				target_port=""
				target_user=""
				target_host=""
			fi
			read_entry="1"
			alias_name=`echo "${line}" | cut -d " " -f 2`
		fi

		if (expr index "$line" '\?' > /dev/null 2>&1) then
			read_entry="0"
			alias_name=""
		fi 

		# skip until next "host", if wildcards were found...
		[[ "$read_entry" = "0" ]] && continue

		if expr match "${line}" "Hostname" > /dev/null 2>&1; then
			target_host=`echo "${line}" | cut -d " " -f 2`
		fi
		if expr match "${line}" "user" > /dev/null 2>&1; then
			target_user="`echo "${line}" | cut -d " " -f 2`@"
		fi
		if expr match "${line}" "port" > /dev/null 2>&1; then
			target_port="-p `echo "${line}" | cut -d " " -f 2`"
		fi
	done 

	IFS=$OLDIFS
}

## rebuild cache only, 
## if ${SSH_CONFIG_FN} is newer than the cache

if [[ ! -r "${CACHE_FN}" ]] || [[ "${SSH_CONFIG_FN}" -nt "${CACHE_FN}" ]]
then
	rm -f ${CACHE_FN}
	__collect_ssh_aliases	
fi

source ${CACHE_FN}