gpdftext: command not found

Have You tried accessing the binary with the full path?

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/gpdftext - from package: gpdftext

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