pmcheck: 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/pmcheck - from package: perl-pmtools

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

On Debian possible default full paths are:

/usr/bin/pmcheck - from package: pmtools

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

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