rcexplain: 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/rcexplain - from package: sra-toolkit

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

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