sha256deep: 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/bin/sha256deep - from package: md5deep

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

On Debian possible default full paths are:

/usr/bin/sha256deep - from package: md5deep

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

Error in other languages:
sha256deep: bevel nie gevind nie
sha256deep: comandă negăsită
sha256deep: comando não encontrado
sha256deep: commande introuvable
sha256deep: command not found
sha256deep: käsku ei ole
sha256deep: không tìm thấy lệnh
sha256deep: komanda nerasta
sha256deep: Kommando nicht gefunden.
sha256deep: kommandot finns inte
sha256deep: komut yok
sha256deep: nie znaleziono polecenia
sha256deep: níor aimsíodh an t-ordú
sha256deep: no se encontró la orden
sha256deep: no s'ha trobat l'ordre
sha256deep: opdracht niet gevonden
sha256deep: parancs nem található
sha256deep: perintah tidak ditemukan
sha256deep: príkaz nenájdený
sha256deep: příkaz nenalezen
sha256deep: команда не найдена
sha256deep: командата не е открита
sha256deep: 命令找不到
sha256deep: コマンドが見つかりません