yedit: 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/yedit - from package: patchy

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

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