feat(cli): added the diff command to display the difference of two files

include/utilities.h

@@ -1,6 +1,9 @@
 #ifndef UTILITIES_H
 #define UTILITIES_H
 
+#include <sys/stat.h>
+#include <errno.h>
+
 #include "file.h"
 #include "action_list.h"
 
@@ -9,6 +12,25 @@
 #define GREEN_BG "\033[42m"
 #define BLACK_FG "\033[30m"
 
+typedef enum {
+    PT_NOEXIST,
+    PT_FILE,
+    PT_DIR,
+    PT_OTHER,
+    PT_ERROR
+} PathType;
+
+PathType get_path_type(const char* path) {
+    struct stat st;
+    int rc = stat(path, &st);
+    if (rc != 0) {
+        return (errno == ENOENT) ? PT_NOEXIST : PT_ERROR;
+    }
+    if (S_ISREG(st.st_mode))  return PT_FILE;
+    if (S_ISDIR(st.st_mode))  return PT_DIR;
+    return PT_OTHER;
+}
+
 void visualize_diff(File* old_version, File* new_version, ActionList* actions) {
     int* deleted_lines = calloc(old_version->lines, sizeof(int));
     int* inserted_lines = calloc(new_version->lines, sizeof(int));