mdurlcheck

Program mdurlcheck checks whether given markdown file has any broken
relative links to other files.

It takes single .md file as an argument, then finds relative links
(including image links) to other files in it and checks whether such files
exist on the filesystem.

Provided with the following file:

    [Document 1](doc1.md), [document 2](doc2.md), and [another
    one](dir/doc.md)

    ![program illustration](img/screenshot.jpg "Screenshot")

The program will check whether files doc1.md, doc2.md, dir/doc.md, and
img/screenshot.jpg exist on disk, relative to the location of provided file.

Program reports any errors on stderr and exits with non-zero exit code.

If you need to check large directory with markdown files for broken
cross-references, use xargs:

    find . -name \*.md -print0 | xargs -0 -P4 -n1 mdurlcheck