Apple2: Provide a way to get directory file count

The information is available in the directory key block. Providing it to the user as soon as opendir() is done can save them costly code.
2024-11-10 13:38:35 +01:00
parent 36132a437b
commit 40d9f3eed5
9 changed files with 64 additions and 14 deletions
--- a/libsrc/apple2/dir_file_count.s
+++ b/libsrc/apple2/dir_file_count.s
@@ -0,0 +1,24 @@
+;
+; Colin Leroy-Mira <colin@colino.net>, 2024
+;
+; unsigned int __fastcall__ dir_file_count(DIR *dir);
+;
+
+        .export   _dir_file_count
+
+        .importzp ptr1
+
+        .include  "apple2.inc"
+        .include  "dir.inc"
+
+.proc _dir_file_count
+        sta       ptr1
+        stx       ptr1+1
+
+        ldy       #DIR::FILE_COUNT + 1
+        lda       (ptr1),y
+        tax
+        dey
+        lda       (ptr1),y
+        rts
+.endproc