1

My question is closely related to LuaTeX: Split path string for use in macros. However, in contrast to this, I would like to have the basename. For example, I am interested in file from /path/to/file.ext or path/to/file.

Using Tex's \filename@parse from Extract filename from path was not possible. The command is not defined. Maybe that's because I am using LuaLaTex.

So, I tried to adapt the Lua-approach. Based on https://github.com/Donearm/scripts/blob/master/lib/basename.lua, I modified the upper code to (note the additionally escaped %):

\newcommand*{\basename}[1]{\directlua{\unexpanded{
    local name = string.gsub([[#1]], "(.*/)(.*)", "\%2")
    tex.sprint(name)
}}}
\basename{/path/to/file.ext}

Unfortunately, It does not output anything!?!

  • 3
    \filename@parse is defined in lualatex. – David Carlisle Apr 15 at 14:59
  • you need to use \@percentchar, \% does not expand to a % token. – David Carlisle Apr 15 at 16:04
  • I didn't get it running with \@percentchar. Anyway, I use \filename@parse now because of its potential backwards compatibility to pdflatex. I have no idea what was wrong with my first implementation. If you post it as an answer I can mark the question as answered. – Chickenmarkus Apr 16 at 7:06
  • I found out why it was not working before. I used it as \tikzsetnextfilename{\filename@parse\filename@base}. Since \tikzsetnextfilename uses \filename@parse for its own it has to be \filename@parse\tikzsetnextfilename{\filename@base} instead. – Chickenmarkus Apr 17 at 7:02
4

\filename@parse is defined in lualatex, the example document that you reference at

Extract filename from path

gives the same results in pdflatex or lualatex.

4

You can easily get the basename in LuaTeX using the FFI and a platform-dependent function. On POSIX-based systems you can use the basename() function.

Because it uses the FFI you have to enable --shell-escape.

In tex.sprint I use the first argument -2 to switch to verbatim catcodes, in case the path contains any characters which are treated special by TeX, such as {}$%#.

\documentclass{article}
\usepackage{luacode}
\begin{luacode*}
local ffi = assert(require("ffi"))

ffi.cdef[[
char *basename(char *path);
]]

function basename(path)
    local cstr = ffi.new("char[?]", #path + 1)
    ffi.copy(cstr, path)
    return ffi.string(ffi.C.basename(cstr))
end
\end{luacode*}
\newcommand*\basename[1]{\directlua{tex.sprint(-2, basename("\luaescapestring{\unexpanded{#1}}"))}}
\begin{document}
\basename{/path/to/file.ext}
\end{document}

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