psbbox.sh: 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/psbbox.sh - from package: GMT

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

On Debian possible default full paths are:

/usr/lib/gmt/bin/psbbox.sh - from package: GMT

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

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