piqsl: 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/piqsl - from package: aqsis

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

On Debian possible default full paths are:

/usr/bin/piqsl - from package: aqsis

You may install the required package with command apt-get install {package}

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