gnu: Add texlive-latex-filemod.

* gnu/packages/tex.scm (texlive-latex-filemod): New variable.

gnu/packages/tex.scm

@@ -1845,6 +1845,44 @@ (define-public texlive-latex-expdlist
 @code{enumerate} lists, and numbered lists remain in sequence).")
     (license license:lppl)))
 
+(define-public texlive-latex-filemod
+  (package
+    (name "texlive-latex-filemod")
+    (version (number->string %texlive-revision))
+    (source (origin
+              (method svn-fetch)
+              (uri (svn-reference
+                    (url (string-append "svn://www.tug.org/texlive/tags/"
+                                        %texlive-tag "/Master/texmf-dist/"
+                                        "/tex/latex/filemod"))
+                    (revision %texlive-revision)))
+              (sha256
+               (base32
+                "0vpxilfw69xv78f03g0j0zw0bw4qcn36whqp8phcq48qk1ax2kr2"))))
+    (build-system trivial-build-system)
+    (arguments
+     `(#:modules ((guix build utils))
+       #:builder
+       (begin
+         (use-modules (guix build utils))
+         (let ((target (string-append (assoc-ref %outputs "out")
+                                      "/share/texmf-dist/tex/latex/filemod")))
+           (mkdir-p target)
+           (copy-recursively (assoc-ref %build-inputs "source") target)
+           #t))))
+    (home-page "http://www.ctan.org/pkg/filemod")
+    (synopsis "Provide file modification times, and compare them")
+    (description
+     "This package provides macros to read and compare the modification dates
+of files.  The files may be @code{.tex} files, images or other files (as long
+as they can be found by LaTeX).  It uses the @code{\\pdffilemoddate} primitive
+of pdfLaTeX to find the file modification date as PDF date string, parses the
+string and returns the value to the user.  The package will also work for DVI
+output with recent versions of the LaTeX compiler which uses pdfLaTeX in DVI
+mode.  The functionality is provided by purely expandable macros or by faster
+but non-expandable ones.")
+    (license license:lppl1.3+)))
+
 (define-public texlive-latex-natbib
   (package
     (name "texlive-latex-natbib")