gbkpdflatex: 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/gbkpdflatex - from package: texlive-east-asian

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

On Debian possible default full paths are:

/usr/bin/gbkpdflatex - from package: latex-cjk-chinese

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

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