somnec: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH

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 Debian possible default full paths are:

/usr/bin/somnec - from package: nec

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