summain: 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/summain - from package: summain

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

On Debian possible default full paths are:

/usr/bin/summain - from package: summain

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

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