diff --git a/example/ex-grep01.c b/example/ex-grep01.c
new file mode 100644
index 00000000..91054d27
--- /dev/null
+++ b/example/ex-grep01.c
@@ -0,0 +1,32 @@
+#include <stdio.h>
+#include "m-string.h"
+#include "m-array.h"
+#include "m-dict.h"
+
+ARRAY_DEF(array_size, size_t)
+#define M_OPL_array_size_t() ARRAY_OPLIST(array_size)
+DICT_DEF2(map_pos, string_t, STRING_OPLIST, array_size_t, ARRAY_OPLIST(array_size))
+#define M_OPL_map_pos_t() DICT_OPLIST(map_pos, STRING_OPLIST, ARRAY_OPLIST(array_size))
+
+int main(int argc, const char *argv[])
+{
+   if (argc == 2) {
+     M_LET(word, string_t)
+     M_LET(positions, map_pos_t) {
+        FILE *f = fopen(argv[1], "rt");
+        if (!f) return 1;
+        while (string_fget_word(word, " \t\n\r\"(),=", f)) {
+          array_size_t *array = map_pos_get_at(positions, word);
+          array_size_push_back(*array, (size_t)ftell(f) - string_size(word));
+        }
+        fclose(f);
+
+        for M_EACH(pair, positions, map_pos_t) {
+         string_fputs(stdout, pair->key);
+         for M_EACH(pos, pair->value, array_size_t)
+            printf(" %zu", *pos);
+         printf("\n");
+        }
+     }
+   }
+}