dmtxwrite: 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/dmtxwrite - from package: libdmtx-utils

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

On Debian possible default full paths are:

/usr/bin/dmtxwrite - from package: dmtx-utils

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

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