xcam: 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 CentOS possible default full paths are:

/usr/bin/xcam - from package: sane-frontends

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/xcam - from package: sane

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

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