In this question we learn that we can use FindFile to get the disk location of a package. However, I have some packages that are installed into my $USER/Library/Mathematica/Applications/$ directory by symbolic link.
I'd like to be able to resolve the "true" path of these packages, much like the GNU readlink utility does. Does Mathematica have such a function built in? If not, by what other [preferably cross-platform] methods can this be accomplished?
AbsoluteFileName will resolve symbolic links.
Example on my machine:
AbsoluteFileName["/Library/TeX/texbin"] (* "/usr/local/texlive/2019/bin/x86_64-darwin" *) After a bit more fiddling around I found FileInformation, an undocumented function which takes a file name as an argument.
FileInformation[FindFile["myPackage"]]` returns
{AbsoluteFileName->/absolute/path/to/myPackage.wl, BlockCount->24, BlockSize->4096, ByteCount->8474, CreationDate->Thu 17 Oct 2019 11:06:04GMT-4., Device->16777220, DirectoryName->$HOME/Library/Mathematica/Applications, FileAttributes->Missing[NotAvailable], FileBaseName->myPackage,FileExtension->wl, FileName->$HOME/Library/Mathematica/Applications/myPackage.wl, FileType->File, GID->20, GroupName->Missing[NotAvailable], Inode->28731823, LastAccessDate->Wed 23 Oct 2019 18:16:13GMT-4., LastModificationDate->Wed 23 Oct 2019 18:16:10GMT-4., LinkCount->1, OwnerName->Missing[NotAvailable], RawByteCount->12288, SetGroupID->False, SetUserID->False, Sticky->False, UID->501, UnixPermissionsCode->0660, UnixPermissionsString->-rw-rw----} where I replaced my home directory with $HOME and the true readlink path with /absolute/path/to/myPackage.wl for privacy. CreationDate, LastAccessDate, and LastModificationDate are DateObjects, all the left-hand sides of the rules are "strings", and the right-hand sides are integers, strings, etc.
SO, what I was looking for was "AbsoluteFileName"/.FileInformation[FindFile["myPackage"]]`