markov: 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/lib64/4ti2/bin/markov - from package: 4ti2

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

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