grap2graph: 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/grap2graph - from package: groff

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

Error in other languages:
grap2graph: bevel nie gevind nie
grap2graph: comandă negăsită
grap2graph: comando não encontrado
grap2graph: commande introuvable
grap2graph: command not found
grap2graph: käsku ei ole
grap2graph: không tìm thấy lệnh
grap2graph: komanda nerasta
grap2graph: Kommando nicht gefunden.
grap2graph: kommandot finns inte
grap2graph: komut yok
grap2graph: nie znaleziono polecenia
grap2graph: níor aimsíodh an t-ordú
grap2graph: no se encontró la orden
grap2graph: no s'ha trobat l'ordre
grap2graph: opdracht niet gevonden
grap2graph: parancs nem található
grap2graph: perintah tidak ditemukan
grap2graph: príkaz nenájdený
grap2graph: příkaz nenalezen
grap2graph: команда не найдена
grap2graph: командата не е открита
grap2graph: 命令找不到
grap2graph: コマンドが見つかりません