did: 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/did - from package: did

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

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