dcraw: 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/dcraw - from package: dcraw

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

On Debian possible default full paths are:

/usr/bin/dcraw - from package: dcraw

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

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