stapsh: 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/stapsh - from package: systemtap-runtime

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

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