tcplay: 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/tcplay - from package: tcplay

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

On Debian possible default full paths are:

/usr/sbin/tcplay - from package: tcplay

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

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