Simple SSH/SFTP manager

ssh_manager.sh

#!/bin/sh

# Simple SSH/SFTP manager
# 
# Created: 2023.05.23
# Updated: 2023.08.24
# 
# Author: Alexey Savin (LamberKeep)

# To run connection manager just run this file.
# 
# Connection list file example:
# user1@hostname1
# user2@hostname1
# user1@hostname2
# user2@hostname2

connection_manager()
{
	cat -n $2

	echo -ne "\nChoose connection: "

	read answer

	if [ $answer -gt $(wc -l < $2) ]
	then
		echo -e "\nNot a option.\n"
		exit 1
	fi

	remote=$(head -n $answer $2 | tail -n 1)
	remoteAddress=$(echo $remote | sed -n 's|.*@||p')
	
	if ! try_to_reach $remoteAddress
	then
		echo "Target not reached"
		exit 1
	fi
	
	clear
	eval $1 $remote
}

try_to_reach()
{
	for attempts in $(seq 1 3)
	do
		echo "[$attempts] Trying to connect: $1"
		if ping -c 1 $1 &> /dev/null
		then
			return 0
		fi

		sleep 10s
	done

	return 1
}

try_help()
{
	echo -e "Try 'sh $(basename $0) --help' for more information.\n"
}

echo -e "\nSimple SSH/SFTP manager\n"

if [ ! -z "$2" ]
then
	if [ -z "$SSH_LIST" ]
	then
		SSH_LIST=$2
	fi

	if [ -z "$SFTP_LIST" ]
	then
		SFTP_LIST=$2
	fi
fi

if [[ $@ =~ "--help" ]]
then
	echo -e "Usage: $(basename $0) [OPTIONS] [FILE]\n\nOptions, with no OPTIONS will use '--ssh' by default:\n\t--help\toutput this help\n\t--ssh\tSSH manager\n\t--sftp\tSFTP manager\n\nWith no FILE will use files with SSH and SFTP addresses from following enviroment variables:\n\tSSH_LIST\n\tSFTP_LIST\n"
	exit 0
fi

if [ ! -f $SSH_LIST -o ! -f $SFTP_LIST ]
then
	echo -e "$(basename $0): no connection list file"
	try_help
	exit 1
fi

case "$1" in
	""|--ssh)
		connection_manager ssh $SSH_LIST
		exit 0
		;;
	--sftp)
		connection_manager sftp $SFTP_LIST
		exit 0
		;;
	--*)
		echo -e "$(basename $0): unrecognized option '$1'"
		try_help
		exit 1
		;;
	*)
		connection_manager ssh $1
		exit 0
		;;
esac