psplit: 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/psplit - from package: ncl

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

On Debian possible default full paths are:

/usr/bin/psplit - from package: ncl-ncarg

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

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