documentclass{article}
usepackage{etoolbox}
usepackage{graphicx}
usepackage{bashful}
begin{document}
renewcommand*{do}[1]{%
The file #1 has size
bash
wc #1
END
bashStdout

}
docsvlist{foo.log,foo.tex}
end{document}

pdflatex --shell-esc  foo.tex

(/usr/local/texlive/2015/texmf-dist/tex/latex/latexconfig/epstopdf-sys.cfg))
! Use of bashIII doesn't match its definition.
<recently read> w

l.17 docsvlist{foo.log,foo.tex}

documentclass{article}
usepackage{etoolbox}
usepackage{graphicx}
usepackage{bashful}
begin{document}
renewcommand*{do}[1]{%
The file #1 has size

}
docsvlist{foo.log,foo.tex}

bash
wc foo.tex
END
bashStdout
end{document}