ec2_gahp: 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/sbin/ec2_gahp - from package: condor

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

On Debian possible default full paths are:

/usr/sbin/ec2_gahp - from package: htcondor

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

Error in other languages:
ec2_gahp: bevel nie gevind nie
ec2_gahp: comandă negăsită
ec2_gahp: comando não encontrado
ec2_gahp: commande introuvable
ec2_gahp: command not found
ec2_gahp: käsku ei ole
ec2_gahp: không tìm thấy lệnh
ec2_gahp: komanda nerasta
ec2_gahp: Kommando nicht gefunden.
ec2_gahp: kommandot finns inte
ec2_gahp: komut yok
ec2_gahp: nie znaleziono polecenia
ec2_gahp: níor aimsíodh an t-ordú
ec2_gahp: no se encontró la orden
ec2_gahp: no s'ha trobat l'ordre
ec2_gahp: opdracht niet gevonden
ec2_gahp: parancs nem található
ec2_gahp: perintah tidak ditemukan
ec2_gahp: príkaz nenájdený
ec2_gahp: příkaz nenalezen
ec2_gahp: команда не найдена
ec2_gahp: командата не е открита
ec2_gahp: 命令找不到
ec2_gahp: コマンドが見つかりません