sockperf: command not found

Have You tried accessing the binary with the full path?

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH

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/sockperf - from package: sockperf

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