pepstats: command not found

Have You tried accessing the binary with the full path?

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/pepstats - from package: emboss

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