countperl: 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/countperl - from package: libperl-metrics-simple-perl

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

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