dolfin-plot: 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/dolfin-plot - from package: dolfin-bin

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