magic files

R/RcppExports.R

@@ -28,3 +28,7 @@ incant <- function(path, magic_db = "system") {
     .Call('wand_incant', PACKAGE = 'wand', path, magic_db)
 }
 
+lib_version <- function() {
+    .Call('wand_lib_version', PACKAGE = 'wand')
+}
+

R/zzz.r

@@ -26,8 +26,10 @@ magic_wand_file <- function(force=FALSE) {
   if (!dir.exists(cache)) dir.create(cache, showWarnings=FALSE)
   if (!dir.exists(cache)) return("system")
 
+  if (lib_version() >= 528) vers <- "new" else vers <- "old"
+
   if (!file.exists(file.path(rappdirs::user_cache_dir("wandr"), "magic.mgc"))) {
-    suppressWarnings(unzip(system.file("magic.mgc.zip", package="wand"),
+    suppressWarnings(unzip(system.file("db", vers, "magic.mgc.zip", package="wand"),
                            exdir=cache, overwrite=force))
   }
 

man/incant.Rd

@@ -22,6 +22,10 @@ a \code{tibble} / \code{data.frame} of file magic attributes.
 \description{
 Retrieve 'magic' attributes from files and directories
 }
+\note{
+Various fields might not be available depending on the version
+  of \code{libmagic} you have installed.
+}
 \examples{
 library(magrittr)
 library(dplyr)

man/magic_wand_file.Rd

@@ -20,8 +20,6 @@ perform the decompression unless \code{force} is \code{TRUE} or the
 cache directory has been cleared.
 }
 \examples{
-library(magrittr)
-library(dplyr)
 
 system.file("img", package="filemagic") \%>\%
   list.files(full.names=TRUE) \%>\%

src/RcppExports.cpp

@@ -17,3 +17,13 @@ BEGIN_RCPP
     return __result;
 END_RCPP
 }
+// lib_version
+int lib_version();
+RcppExport SEXP wand_lib_version() {
+BEGIN_RCPP
+    Rcpp::RObject __result;
+    Rcpp::RNGScope __rngScope;
+    __result = Rcpp::wrap(lib_version());
+    return __result;
+END_RCPP
+}

src/wand.cpp

@@ -145,3 +145,6 @@ DataFrame incant(CharacterVector path, std::string magic_db="system") {
   return(df);
 
 }
+
+// [[Rcpp::export]]
+int lib_version() { return(magic_version()); }