4.19 Paths

When you typeset long pathnames, electronic mail addresses, or other such “computer” names, you would like TeX to break lines at punctuation characters within the name, rather than trying to find hyphenation points within the words. For example, it would be better to break the email address letters@alpha.gnu.ai.mit.edu at the `@' or a `.', rather than at the hyphenation points in `letters' and `alpha'.

If you use the \path macro to typeset the names, TeX will find these good breakpoints. The argument to \path is delimited by any character other other than `\' which does not appear in the name itself. `|' is often a good choice, as in:

     \path|letters@alpha.gnu.ai.mit.edu|

You can control the exact set of characters at which breakpoints will be allowed by calling \discretionaries. This takes the same sort of delimited argument; any character in the argument will henceforth be a valid breakpoint within \path. The default set is essentially all the punctuation characters:

     \discretionaries |~!@$%^&*()_+`-=#{}[]:";'<>,.?\/|

If for some reason you absolutely must use \ as the delimiter character for \path, you can set \specialpathdelimiterstrue. (Other delimiter characters can still be used.) TeX then processes the \path argument about four times more slowly.

The \path macro comes from path.sty, written by Nelson Beebe and Philip Taylor and available at http://www.ctan.org/tex-archive/macros/latex/contrib/misc/path.sty.