owish: 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/owish - from package: otcl-shells

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

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