add is_symlink, create_symlink, read_symlink. Improve test coverage

Author: scivision

+stdlib/+fileio/canonical.m

@@ -4,6 +4,8 @@
   p (1,1) string
 end
 
+import java.io.File
+
 % have to expand ~ first (like C++ filesystem::path::absolute)
 c = stdlib.fileio.expanduser(p);
 
@@ -28,6 +30,6 @@
 % REQUIRES path to exist, while java method does not.
 % c = builtin('_canonicalizepath', c);
 
-c = stdlib.fileio.posix(string(java.io.File(c).getCanonicalPath()));
+c = stdlib.fileio.posix(File(c).getCanonicalPath());
 
 end % function

+stdlib/+fileio/create_symlink.m

@@ -0,0 +1,32 @@
+function ok = create_symlink(target, link)
+%% create_symlink create symbolic link
+% https://docs.oracle.com/en/java/javase/21/docs/api/java.base/java/nio/file/Files.html#createSymbolicLink(java.nio.file.Path,java.nio.file.Path,java.nio.file.attribute.FileAttribute...)
+
+arguments
+  target (1,1) string
+  link (1,1) string
+end
+
+% import java.io.File
+% import java.nio.file.Files
+% ok = Files.createSymbolicLink(File(link).toPath(), File(target).toPath());
+% the above should work, but Matlab Java doesn't recognize the optional argument omitted.
+
+if stdlib.fileio.exists(link)
+  warning("link %s already exists", link)
+  ok = false;
+  return
+end
+
+if ispc
+  cmd = "pwsh -c " + '"' + "New-Item -ItemType SymbolicLink -Path " + link + " -Target " + target + '"';
+else
+  cmd = "ln -s " + target + " " + link;
+end
+
+% suppress output text on powershell
+[stat, ~] = system(cmd);
+
+ok = stat == 0;
+
+end

+stdlib/+fileio/is_absolute_path.m

@@ -4,7 +4,9 @@
   apath (1,1) string
 end
 
+import java.io.File
+
 % expanduser() here to work like C++ filesystem::path::is_absolute()
-isabs = java.io.File(stdlib.fileio.expanduser(apath)).isAbsolute();
+isabs = File(stdlib.fileio.expanduser(apath)).isAbsolute();
 
 end

+stdlib/+fileio/is_readable.m

@@ -6,7 +6,10 @@
   file (1,1) string
 end
 
+import java.io.File
+import java.nio.file.Files
 
-ok = java.nio.file.Files.isReadable(java.io.File(stdlib.fileio.absolute_path(file)).toPath());
+
+ok = Files.isReadable(File(stdlib.fileio.absolute_path(file)).toPath());
 
 end

+stdlib/+fileio/is_symlink.m

@@ -0,0 +1,16 @@
+function ok = is_symlink(p)
+%% is_symlink is path symbolic link
+% https://docs.oracle.com/en/java/javase/21/docs/api/java.base/java/nio/file/Files.html#isSymbolicLink(java.nio.file.Path)
+
+arguments
+  p (1,1) string
+end
+
+import java.io.File
+import java.nio.file.Files
+
+% must be absolute path
+f = File(stdlib.fileio.absolute_path(p)).toPath();
+ok = Files.isSymbolicLink(f);
+
+end

+stdlib/+fileio/is_writable.m

@@ -6,6 +6,10 @@
   file (1,1) string
 end
 
-ok = java.nio.file.Files.isWritable(java.io.File(stdlib.fileio.absolute_path(file)).toPath());
+import java.io.File
+import java.nio.file.Files
+
+
+ok = Files.isWritable(File(stdlib.fileio.absolute_path(file)).toPath());
 
 end

+stdlib/+fileio/normalize.m

@@ -5,6 +5,9 @@
   p (1,1) string
 end
 
-n = stdlib.fileio.posix(java.io.File(stdlib.fileio.expanduser(p)).toPath().normalize());
+import java.io.File
+import stdlib.fileio.expanduser
+
+n = stdlib.fileio.posix(File(expanduser(p)).toPath().normalize());
 
 end

+stdlib/+fileio/read_symlink.m

@@ -0,0 +1,26 @@
+function r = read_symlink(p)
+%% read_symlink read symbolic link
+arguments
+  p (1,1) string
+end
+
+import java.io.File
+import java.nio.file.Files
+
+r = stdlib.fileio.absolute_path(p);
+if ~stdlib.fileio.exists(r)
+  warning("%s does not exist", r)
+  r = string.empty;
+  return
+end
+if ~stdlib.fileio.is_symlink(r)
+  warning("%s is not a symlink", r)
+  r = string.empty;
+  return
+end
+
+% https://docs.oracle.com/en/java/javase/21/docs/api/java.base/java/nio/file/Files.html#readSymbolicLink(java.nio.file.Path)
+% must be absolute path
+r = Files.readSymbolicLink(File(r).toPath());
+
+end

+stdlib/+fileio/resolve.m

@@ -5,6 +5,8 @@
   p (1,1) string
 end
 
+import java.io.File
+
 % have to expand ~ first (like C++ filesystem::path::absolute)
 c = stdlib.fileio.expanduser(p);
 
@@ -18,12 +20,8 @@
   c = stdlib.fileio.join(pwd, c);
 end
 
-% similar benchmark time as java method
-% REQUIRES path to exist, while java method does not.
-% c = builtin('_canonicalizepath', c);
-
 % % https://docs.oracle.com/en/java/javase/21/docs/api/java.base/java/io/File.html#getCanonicalPath()
 
-c = stdlib.fileio.posix(string(java.io.File(c).getCanonicalPath()));
+c = stdlib.fileio.posix(File(c).getCanonicalPath());
 
 end % function

+stdlib/+fileio/samepath.m

@@ -5,18 +5,20 @@
   path2 (1,1) string
 end
 
+import java.io.File
+import java.nio.file.Files
+import stdlib.fileio.canonical
+
+issame = false;
 % java.nio.file.Files needs CANONICAL -- not just absolute path
-p1 = java.io.File(stdlib.fileio.canonical(path1)).toPath();
-p2 = java.io.File(stdlib.fileio.canonical(path2)).toPath();
+p1 = canonical(path1);
+if ~stdlib.fileio.exists(p1), return, end
+p1 = File(p1).toPath();
 
-try
-  issame = java.nio.file.Files.isSameFile(p1, p2);
-catch e
-  if e.identifier == "MATLAB:Java:GenericException" && contains(e.message, "NoSuchFileException")
-    issame = false;
-  else
-    rethrow(e)
-  end
-end
+p2 = canonical(path2);
+if ~stdlib.fileio.exists(p2), return, end
+p2 = File(p2).toPath();
+
+issame = Files.isSameFile(p1, p2);
 
 end