tn5250: 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/tn5250 - from package: tn5250

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

Error in other languages:
tn5250: bevel nie gevind nie
tn5250: comandă negăsită
tn5250: comando não encontrado
tn5250: commande introuvable
tn5250: command not found
tn5250: käsku ei ole
tn5250: không tìm thấy lệnh
tn5250: komanda nerasta
tn5250: Kommando nicht gefunden.
tn5250: kommandot finns inte
tn5250: komut yok
tn5250: nie znaleziono polecenia
tn5250: níor aimsíodh an t-ordú
tn5250: no se encontró la orden
tn5250: no s'ha trobat l'ordre
tn5250: opdracht niet gevonden
tn5250: parancs nem található
tn5250: perintah tidak ditemukan
tn5250: príkaz nenájdený
tn5250: příkaz nenalezen
tn5250: команда не найдена
tn5250: командата не е открита
tn5250: 命令找不到
tn5250: コマンドが見つかりません