gnunet-identity: 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/gnunet-identity - from package: gnunet

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

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