praat-open-files: 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/praat-open-files - from package: praat

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

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