Suppressing unwanted command line output when running pdflatex

You can start batchmode earlier by specifying it on the commandline

pdflatex -interaction=batchmode   myfile.tex

Or if you don't even want

This is pdfTeX, Version 3.1415926-2.5-1.40.14 (TeX Live 2013)
 restricted \write18 enabled.
entering extended mode

You could use

pdflatex  myfile > /dev/null

or whatever null output stream is applicable to your operating system.