pisg: 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
/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/pisg - from package: pisg

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

On Debian possible default full paths are:

/usr/bin/pisg - from package: pisg

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