zbarimg: 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/zbarimg - from package: zbar

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

On Debian possible default full paths are:

/usr/bin/zbarimg - from package: zbar-tools

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

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