pgawk: 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/pgawk - from package: gawk

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

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