csvjoin: 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/csvjoin - from package: python-ngram

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

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