pdftex: 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/pdftex - from package: texlive

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

On Debian possible default full paths are:

/usr/bin/pdftex - from package: texlive-binaries

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

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