bar: 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/bar - from package: bar

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

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