tcpick: 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/sbin/tcpick - from package: tcpick

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

On Debian possible default full paths are:

/usr/sbin/tcpick - from package: tcpick

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

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