prev: 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/mh/prev - from package: nmh

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

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