ocs: 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/ocs - from package: cscope

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

On Debian possible default full paths are:

/usr/bin/ocs - from package: cscope

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

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