attr: 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/attr - from package: attr

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

On Debian possible default full paths are:

/usr/bin/attr - from package: attr

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

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