barcode: 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/barcode - from package: barcode

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

On Debian possible default full paths are:

/usr/bin/barcode - from package: barcode

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

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