main.tex: command not found

Have You tried accessing the binary with the full path?

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 Debian possible default full paths are:

/usr/share/doc/whizzytex/examples/bin/main.tex - from package: whizzytex

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