bzgrep: 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/bzgrep - from package: bzip2

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

On Debian possible default full paths are:

/bin/bzgrep - from package: bzip2

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

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