propwatch: 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/propwatch - from package: xawtv

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

On Debian possible default full paths are:

/usr/bin/propwatch - from package: xawtv-tools

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

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