shutdown.sh: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/share/tomcat7/bin/shutdown.sh - from package: tomcat7-common
/usr/share/tomcat8/bin/shutdown.sh - from package: tomcat8-common

You may install the required package with command apt-get install {package}

Error in other languages:
shutdown.sh: bevel nie gevind nie
shutdown.sh: comandă negăsită
shutdown.sh: comando não encontrado
shutdown.sh: commande introuvable
shutdown.sh: command not found
shutdown.sh: käsku ei ole
shutdown.sh: không tìm thấy lệnh
shutdown.sh: komanda nerasta
shutdown.sh: Kommando nicht gefunden.
shutdown.sh: kommandot finns inte
shutdown.sh: komut yok
shutdown.sh: nie znaleziono polecenia
shutdown.sh: níor aimsíodh an t-ordú
shutdown.sh: no se encontró la orden
shutdown.sh: no s'ha trobat l'ordre
shutdown.sh: opdracht niet gevonden
shutdown.sh: parancs nem található
shutdown.sh: perintah tidak ditemukan
shutdown.sh: príkaz nenájdený
shutdown.sh: příkaz nenalezen
shutdown.sh: команда не найдена
shutdown.sh: командата не е открита
shutdown.sh: 命令找不到
shutdown.sh: コマンドが見つかりません