freefem: 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/freefem - from package: freefem

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

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