Preserve permissions when copying files

Makefile

@@ -59,7 +59,11 @@ test:
 		./$(EXECFILE) $(TEST_RULES) $(TEST_DOTFILES) $(TEST_DEST_DIR); \
 	fi
 	diff $(DIFF_FLAGS) $(TEST_DEST_DIR) $(TEST_EXPECTED_DIR)
-
+	if [ ! -x "$(TEST_DEST_DIR)/binary_file" ]; then \
+		@echo "Expected binary_file to be executable."; \
+		exit 1; \
+	fi
+	@echo "*** All tests successfully passed. ***"
 
 clean:
 	rm -f $(OBJS)

README.md

@@ -8,11 +8,10 @@ Many developers store their dotfiles in git repositories, allowing them to share
 * Make string substitutions in files according to configuration files.
 * Include or exclude chunks of files according to configuration file feature flags.
 * Binary files are copied without templating.
+* File permissions are preserved -- executable scripts will remain executable.
 
 ## Known Bugs
-* File permissions are not preserved. This mostly affects executable scripts. After templating they must manually be set executable.
-
-Please report any bugs, difficulties, or suggestions in the issue tracker.
+I fixed all I could find. Please report any bugs, difficulties, or suggestions in the issue tracker.
 
 ### Planned Features
 You tell me!

dottemplater.c

@@ -77,6 +77,7 @@ int walker(const char *fpath, const struct stat *sb,
         } else {
             copy_file(fpath, dest_file);
         }
+        copy_permission(fpath, dest_file);
     }
 
     free(dest_file);

util.c

@@ -150,3 +150,14 @@ void copy_file(const char *src, const char *dest)
     close(input_file);
     close(output_file);
 }
+
+void copy_permission(const char *src, const char *dest)
+{
+    struct stat s;
+    stat(src, &s);
+
+    if (chmod(dest, s.st_mode) < 0) {
+        perror("chmod");
+        exit(1);
+    }
+}

util.h

@@ -21,3 +21,6 @@ bool is_binary_file(const char *fpath);
 
 /** Copies a src file to a destination file.*/
 void copy_file(const char *src, const char *dest);
+
+/** Duplicates permissions on src to dest. */
+void copy_permission(const char *src, const char *dest);