circuits: 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/lib64/4ti2/bin/circuits - from package: 4ti2

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

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