tcpwatch-httpproxy: 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/tcpwatch-httpproxy - from package: tcpwatch-httpproxy

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

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