esniper: 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/esniper - from package: esniper

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