cernlib-static: 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/cernlib-static - from package: cernlib-utils

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

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