retext: 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/retext - from package: retext

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

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