traffic_logcat: 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/traffic_logcat - from package: trafficserver

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

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