csplit: 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/csplit - from package: coreutils

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

On Debian possible default full paths are:

/usr/bin/csplit - from package: coreutils

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

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