sqsh: 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/bin/sqsh - from package: sqsh

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

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