How to obtain absolute path of a file

Question

Many languages provide functions to obtain the absolute path of a file. I wonder if Tex/LaTex has also such macros.

In the following example, given a file name, test if this file really exists. Then, if yes, output its absolute path(including file name) from root like /home/foo/bar/myfile or /c/Program Files/foo/bar/myfile.tex.

Example:

\documentclass{article}
\ExplSyntaxOn
\NewDocumentCommand\getabsolutepath{m}{
  \file_if_exist:nTF {#1}
  {
    % output the absolute path of the file name #1
  }
  {do some other things}
}
\ExplSyntaxOff
\begin{document}
% Given that the current path names "cp". A file named "a.tex" locates in its subdirectory "sub". 
% The typesets of the following invokations of \getabsolutepath should be absolutely the same when file "a" really exists because they refer to the same file.
\getabsolutepath{sub/a}
\getabsolutepath{./sub/a}
\getabsolutepath{./sub/a.tex}
\getabsolutepath{../cp/sub/a}
\end{document}

https://tex.stackexchange.com/questions/42417/full-path-of-current-file — Ingmar, Jul 15 '22 at 07:30
Thank you for this info. Anyway, I don't think this meets my requirement. Those solutions needs working with \input ...and so on. What I want is just giving a file name and obtain its absolute path from root if the file really exists. — lyl, Jul 15 '22 at 08:02
@Ingmar \CurrentFilePath doesn't give the absolute path. You need the currfile package (and you must use the --recorder option) to get the full absolute path of a file. — Ulrike Fischer, Jul 15 '22 at 09:37
Related: Lua solution luatex - Is it possible to use Lua to obtain the current working directory? - TeX - LaTeX Stack Exchange — user202729, Aug 06 '22 at 06:27

score 1 · Answer 1 · edited Jul 20 '22 at 08:39

1

You can use kpsewhich although for files found relative to the working directory, you may want to have $PWD rather than . in the path so the full path is reported. This command is allowed without --shell-escape in the default configuration of texlive (and I think also miktex)

\documentclass{article}
\def\getabsolutepath#1{\input{|kpsewhich "#1"}}
\begin{document}
\getabsolutepath{article.cls}
\getabsolutepath{plain.tex}
\getabsolutepath{\jobname}
\end{document}

called by:

TEXINPUTS=$PWD: pdflatex  cc434

edited Jul 20 '22 at 08:39

user202729

7,143

answered Jul 15 '22 at 13:25

David Carlisle

757,742

Side note, use @@input for an expandable version, I think. With some additional complications of everyeof etc. – user202729 Jul 15 '22 at 13:28
@user202729 hmm -c appears not to work in restricted mode , I'd better edit – David Carlisle Jul 15 '22 at 13:32
@David Carlisle The above code failed to pass complilation in my computer (win7+miktex). showed `(e:\MyOffice\Emacs_Related\Miktex\texmfs\install\tex/latex/base\ts1cmr.fd) ( ! Missing $ inserted. $ l.2 e:/MyOffice/Emacs_ Related/Miktex/texmfs/install/tex/latex/base/article.cls )` – lyl Jul 15 '22 at 13:33
@lyl ah you need a \detokenize or locally set catcode of _ to 12 if you have fancy characters like that – David Carlisle Jul 15 '22 at 13:36
And where can I find the meaning of kpsewhich and texosquery -c? Why needs \def\fcln{/} and \def\fslh{/}? – lyl Jul 15 '22 at 13:39
1

texdoc texosquery and texdoc kpsewhich have more information @lyl – David Carlisle Jul 15 '22 at 13:42
Running \getabsolutepath{\jobname} obtain a typeset of kpsewhich: security risk: running with elevated privileges ./!00-test.tex. I'd like a typeset like /e/.../.../!00-test.tex` – lyl Jul 15 '22 at 13:47
why are you running with elevated privileges ? – David Carlisle Jul 15 '22 at 14:44
I don't know the meaning of the error message – lyl Jul 16 '22 at 02:17
@lyl it is a windows operating message not a tex one, warning you are running the command as adminstrator not normal user access. – David Carlisle Jul 16 '22 at 07:31
Alternative solution includes \sys_get_shell:nnN etc. Write18: capturing shell (script) output as command/variable? - TeX - LaTeX Stack Exchange although you can't use quotes in that case. Side note, TeXlive appears to hard code kpsewhich or something, so for example if you execute kpsewhich a.tex;echo 1 it will (unsafely) do the echo with shell-escape, but do nothing without -- i.e. you seems to be safe against shell injection. – user202729 Aug 05 '22 at 11:44
@user202729 I wouldn't give an answer which requireds shell escape. – David Carlisle Aug 05 '22 at 15:15
Not really, \sys_get_shell works if and only if your solution works. i.e. restricted shell escape mode – user202729 Aug 05 '22 at 15:22
@user202729 ah sorry yes I was confused by your echo example – David Carlisle Aug 05 '22 at 15:27

How to obtain absolute path of a file

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