showserver: 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/showserver - from package: emboss

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

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