LaTeX.org

There's too many texmf file folds, such as /etc/texmf, /home/yonggang/texmf, /usr/share/texmf, /usr/local/texmf and many others. But my system always use the second, that is, /home/yonggang/texmf, I don't know when it was created. I am more familiar with Miktex in windows, but it does not support ...

Thank you, Stefan!
I tried your first suggestion, that is, remove the prefix 'file://', and it can find the files rightly.
But there's another question, how to change the referring path, such as TEXMFHOME? In the texmf.cnf file, I have changed it to the real path my texlive installed, but it still ...

Can tlmgr update texlive packages offline? I have downloaded all the files in the tlnet fold from the website to my local disk, including fold ARCHIVE and TLPKG, and the repository option is set to the local fold like 'file:/home/tlnet'. If I install a new package, it always tell me that: ' Cannot ...