tcpdmatch: 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/tcpdmatch - from package: tcp_wrappers

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

On Debian possible default full paths are:

/usr/sbin/tcpdmatch - from package: tcpd

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

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