texlive下面有很多程序执行ruby脚本

比如pstopdf的, 以前用的都是ps2pdf.exe
现在这儿是用
>texmfstart --verbose pstopdf.rb beamertest.ps
texmfstart version 2.0.3
locating 'pstopdf.rb' in current path '.'
locating 'pstopdf.rb' in caller path './../ruby'
kpse     : direct (forced)
using kpsewhich variable RUBYINPUTS
testing './pstopdf.rb'
testing 'e:/texlive/texmf-dist/scripts/context/ruby/pstopdf.rb'
registering 'pstopdf' as 'e:/texlive/texmf-dist/scripts/context/ruby/pstopdf.rb'

registering 'THREAD' as 'e:/texlive/texmf-dist/scripts/context/ruby'
starting pstopdf.rb
using 'system' call: ruby e:/texlive/texmf-dist/scripts/context/ruby/pstopdf.rb
beamertest.ps

execution failed

装上ruby后就okay了.