ewfexport: 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 CentOS possible default full paths are:

/usr/bin/ewfexport - from package: ewftools

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

On Debian possible default full paths are:

/usr/bin/ewfexport - from package: ewf-tools

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