tcpslice: 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/tcpslice - from package: tcpdump

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

On Debian possible default full paths are:

/usr/sbin/tcpslice - from package: tcpslice

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

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