(enh) Update usage help, add -v and -h

src/cli/main.c

@@ -3,23 +3,27 @@
 
 #include "os.h"
 #include "vm.h"
+#include "path.h"
 #include "wren.h"
 
-int main(int argc, const char* argv[])
-{
-  if (argc == 2 && strcmp(argv[1], "--help") == 0)
+int main(int argc, const char* argv[]) {
+  Path* p = pathNew(argv[0]);
+  pathBaseName(p);
+  char* cli  = p->chars;
+
+  if (argc == 2 && (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-h") == 0))
   {
-    printf("Usage: wren [file] [arguments...]\n");
+    printf("Usage: %s [options] [ file.wren ] [arguments...] \n", cli);
     printf("\n");
-    printf("Optional arguments:\n");
-    printf("  --help     Show command line usage\n");
-    printf("  --version  Show version\n");
+    printf("Options:\n");
+    printf("  -h, --help          Show command line usage\n");
+    printf("  -v, --version       Show version\n");
     return 0;
   }
 
-  if (argc == 2 && strcmp(argv[1], "--version") == 0)
+  if (argc == 2 && (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-v") == 0))
   {
-    printf("wren %s\n", WREN_VERSION_STRING);
+    printf("%s %s\n", cli, WREN_VERSION_STRING);
     return 0;
   }
 

src/cli/path.c

@@ -131,6 +131,20 @@ void pathFree(Path* path)
   free(path);
 }
 
+void pathBaseName(Path* path) {
+  int pos = 0;
+  for (size_t i = path->length - 1; i >=0 ; i--)
+  {
+    if (isSeparator(path->chars[i]))
+    {
+      pos = i;
+      break;
+    }
+  }
+  if (pos == 0) return;
+  strcpy(path->chars, (char*)path->chars + pos + 1);
+}
+
 void pathDirName(Path* path)
 {
   // Find the last path separator.

src/cli/path.h

@@ -41,6 +41,9 @@ void pathFree(Path* path);
 // Strips off the last component of the path name.
 void pathDirName(Path* path);
 
+// returns the basename of the path
+void pathBaseName(Path* path);
+
 // Strips off the file extension from the last component of the path.
 void pathRemoveExtension(Path* path);