condor_userlog: command not found

Have You tried accessing the binary with the full path?

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/condor_userlog - from package: condor

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

On Debian possible default full paths are:

/usr/bin/condor_userlog - from package: htcondor

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