gift-dtd-to-tex.pl: 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/gift-dtd-to-tex.pl - from package: gnuift-perl

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