mev: 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 CentOS possible default full paths are:

/usr/bin/mev - from package: gpm

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/mev - from package: gpm

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

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