detex: 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/detex - from package: texlive-binaries

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

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