websockify: 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
/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/websockify - from package: python-websockify

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

On Debian possible default full paths are:

/usr/bin/websockify - from package: websockify

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