gd2togif: 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/gd2togif - from package: gd-progs

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

On Debian possible default full paths are:

/usr/bin/gd2togif - from package: libgd-tools

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

Error in other languages:
gd2togif: bevel nie gevind nie
gd2togif: comandă negăsită
gd2togif: comando não encontrado
gd2togif: commande introuvable
gd2togif: command not found
gd2togif: käsku ei ole
gd2togif: không tìm thấy lệnh
gd2togif: komanda nerasta
gd2togif: Kommando nicht gefunden.
gd2togif: kommandot finns inte
gd2togif: komut yok
gd2togif: nie znaleziono polecenia
gd2togif: níor aimsíodh an t-ordú
gd2togif: no se encontró la orden
gd2togif: no s'ha trobat l'ordre
gd2togif: opdracht niet gevonden
gd2togif: parancs nem található
gd2togif: perintah tidak ditemukan
gd2togif: príkaz nenájdený
gd2togif: příkaz nenalezen
gd2togif: команда не найдена
gd2togif: командата не е открита
gd2togif: 命令找不到
gd2togif: コマンドが見つかりません