tikz_to_pdf.tex

\documentclass{article}

% by default, final versions do not use tikz
\newif\ifdotikz\dotikzfalse

% drafts do tikz, final versions do not:
% comment out next line for final version
\dotikztrue

\usepackage{graphicx}

\ifdotikz
\usepackage{tikz}
%%% SET JOBNAME TO THE FILENAME HERE %%%
\pgfrealjobname{tikz_to_pdf}
\else
\long\def\beginpgfgraphicnamed#1#2\endpgfgraphicnamed{\includegraphics{#1}}
\fi

\begin{document}

%%% RUN THE NEXT COMMAND WITH \dotikztrue
%%% TO GENERATE out.pdf FROM tikz_to_pdf.tex
%%%
%%% $ pdflatex --jobname=hello tikz_to_pdf
%%%
%%% IF YOU HAVE MORE THAN ONE
%%% \beginpgfgraphicnamed\endpgfgraphicnamed
%%% BLOCK IN YOUR TEX FILE, YOU CAN RUN
%%%
%%% $ sed -n 's/\\beginpgfgraphicnamed{\([^\{\}]*\)}/\1/p' the_texfile.tex | xargs -t -I{} pdflatex --jobname={} the_texfile.tex

\beginpgfgraphicnamed{hello}
\begin{tikzpicture}
%%%% PUT TikZ code HERE %%%%
\pgftext[base]{Hello world.}
%%%% END %%%%
\end{tikzpicture}
\endpgfgraphicnamed

\end{document}