peas-demo: 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/peas-demo - from package: libpeas-doc

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

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