tripwire: 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/sbin/tripwire - from package: tripwire

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

On Debian possible default full paths are:

/usr/sbin/tripwire - from package: tripwire

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

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