srs: 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 Debian possible default full paths are:

/usr/bin/srs - from package: srs

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

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