ylistb-g77: 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/ylistb-g77 - from package: patchy-g77

You may install the required package with command yum install {package}
Error in other languages:
ylistb-g77: bevel nie gevind nie
ylistb-g77: comandă negăsită
ylistb-g77: comando não encontrado
ylistb-g77: commande introuvable
ylistb-g77: command not found
ylistb-g77: käsku ei ole
ylistb-g77: không tìm thấy lệnh
ylistb-g77: komanda nerasta
ylistb-g77: Kommando nicht gefunden.
ylistb-g77: kommandot finns inte
ylistb-g77: komut yok
ylistb-g77: nie znaleziono polecenia
ylistb-g77: níor aimsíodh an t-ordú
ylistb-g77: no se encontró la orden
ylistb-g77: no s'ha trobat l'ordre
ylistb-g77: opdracht niet gevonden
ylistb-g77: parancs nem található
ylistb-g77: perintah tidak ditemukan
ylistb-g77: príkaz nenájdený
ylistb-g77: příkaz nenalezen
ylistb-g77: команда не найдена
ylistb-g77: командата не е открита
ylistb-g77: 命令找不到
ylistb-g77: コマンドが見つかりません