sshow: 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/sshow - from package: dsniff

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

On Debian possible default full paths are:

/usr/sbin/sshow - from package: dsniff

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

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