rospack: 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/rospack - from package: rospack

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

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