Add predicate copy_file/2 in library(files)

src/lib/files.pl

@@ -70,8 +70,9 @@ In this library, directories and files are represented as
                   file_exists/1,
                   directory_exists/1,
                   delete_file/1,
-				  rename_file/2,
-				  delete_directory/1,
+		  rename_file/2,
+		  copy_file/2,
+		  delete_directory/1,
                   make_directory/1,
                   make_directory_path/1,
                   working_directory/2,
@@ -150,6 +151,11 @@ rename_file(File, Renamed) :-
         must_be(chars, Renamed),
         '$rename_file'(File, Renamed).
 
+copy_file(File, Copied) :-
+	file_must_exist(File, copy_file/2),
+	must_be(chars, Copied),
+	'$copy_file'(File, Copied).
+
 %% delete_directory(+Directory).
 %
 % Succeeds if Directory is deleted from the current system.

src/machine/dispatch.rs

@@ -3533,6 +3533,14 @@ impl Machine {
                     self.rename_file();
                     step_or_fail!(self, self.machine_st.p = self.machine_st.cp);
                 }
+		&Instruction::CallCopyFile(_) => {
+		    self.copy_file();
+		    step_or_fail!(self, self.machine_st.p += 1);
+		}
+		&Instruction::ExecuteCopyFile(_) => {
+		    self.copy_file();
+		    step_or_fail!(self, self.machine_st.p = self.machine_st.cp);
+		}
                 &Instruction::CallWorkingDirectory(_) => {
                     try_or_throw!(self.machine_st, self.working_directory());
                     step_or_fail!(self, self.machine_st.p += 1);

src/machine/system_calls.rs

@@ -1653,6 +1653,19 @@ impl Machine {
         self.machine_st.fail = true;
     }
 
+    #[inline(always)]
+    pub(crate) fn copy_file(&mut self) {
+	if let Some(file) = self.machine_st.value_to_str_like(self.machine_st.registers[1]) {
+	    if let Some(copied) = self.machine_st.value_to_str_like(self.machine_st.registers[2]) {
+		if fs::copy(file.as_str(), copied.as_str()).is_ok() {
+		    return;
+		}
+	    }
+	}
+
+	self.machine_st.fail = true;
+    }
+
     #[inline(always)]
     pub(crate) fn delete_directory(&mut self) {
         if let Some(dir) = self.machine_st.value_to_str_like(self.machine_st.registers[1]) {