pepdigest: 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/pepdigest - from package: emboss

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

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