dvigif: 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/dvigif - from package: dvipng

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

On Debian possible default full paths are:

/usr/bin/dvigif - from package: dvipng

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

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