picogcnf: 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/picogcnf - from package: picosat

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

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