gtk-sharp2-examples-list: 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/gtk-sharp2-examples-list - from package: gtk-sharp2-examples

You may install the required package with command apt-get install {package}
Error in other languages:
gtk-sharp2-examples-list: bevel nie gevind nie
gtk-sharp2-examples-list: comandă negăsită
gtk-sharp2-examples-list: comando não encontrado
gtk-sharp2-examples-list: commande introuvable
gtk-sharp2-examples-list: command not found
gtk-sharp2-examples-list: käsku ei ole
gtk-sharp2-examples-list: không tìm thấy lệnh
gtk-sharp2-examples-list: komanda nerasta
gtk-sharp2-examples-list: Kommando nicht gefunden.
gtk-sharp2-examples-list: kommandot finns inte
gtk-sharp2-examples-list: komut yok
gtk-sharp2-examples-list: nie znaleziono polecenia
gtk-sharp2-examples-list: níor aimsíodh an t-ordú
gtk-sharp2-examples-list: no se encontró la orden
gtk-sharp2-examples-list: no s'ha trobat l'ordre
gtk-sharp2-examples-list: opdracht niet gevonden
gtk-sharp2-examples-list: parancs nem található
gtk-sharp2-examples-list: perintah tidak ditemukan
gtk-sharp2-examples-list: príkaz nenájdený
gtk-sharp2-examples-list: příkaz nenalezen
gtk-sharp2-examples-list: команда не найдена
gtk-sharp2-examples-list: командата не е открита
gtk-sharp2-examples-list: 命令找不到
gtk-sharp2-examples-list: コマンドが見つかりません