Moved most of the file type detection from cbm_dir.c into a new function

called _cbm_filetype().
Added an assembler include file with the file type definitions from cbm.h.
Added a first implementation of readdir() for the CBMs.


git-svn-id: svn://svn.cc65.org/cc65/trunk@5669 b7a2c559-68d2-44c3-8de9-860c34a00d81

libsrc/cbm/readdir.c

@@ -0,0 +1,131 @@
+/*
+ * Ullrich von Bassewitz, 2012-05-30. Based on code by Groepaz.
+ */
+
+
+
+#include <stdlib.h>
+#include <string.h>
+#include <dirent.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <errno.h>
+#include <cbm.h>
+#include "dir.h"
+
+#include <stdio.h>
+
+
+struct dirent* __fastcall__ readdir (register DIR* dir)
+{
+    static struct dirent entry;
+    register unsigned char* b;
+    register unsigned char i;
+    unsigned char count;
+    unsigned char j;
+    unsigned char s;
+    unsigned char buffer[0x40];
+
+
+    /* Remember the directory offset for this entry */
+    entry.d_off = dir->off;
+
+    /* Skip the basic line-link */
+    if (!_dirskip (2, dir)) {
+        /* errno already set */
+        goto exit;
+    }
+    dir->off += 2;
+
+    /* Read the number of blocks */
+    if (read (dir->fd, &entry.d_blocks, sizeof (entry.d_blocks)) !=
+        sizeof (entry.d_blocks)) {
+        goto error;
+    }
+
+    /* Read the next file entry into the buffer */
+    for (count = 0, b = buffer; count < sizeof (buffer); ++count, ++b) {
+        if (read (dir->fd, b, 1) != 1) {
+            /* ### Check for EOF */
+            goto error;
+        }
+        if (*b == '\0') {
+            break;
+        }
+    }
+
+    /* End of directory is reached if the buffer contains "blocks free". It is
+     * sufficient here to check for the leading 'b'. To avoid problems if we're
+     * called again, read until end of directory.
+     */
+    if (count > 0 && buffer[0] == 'b') {
+        while (read (dir->fd, buffer, 1) == 1) ;
+        return 0;
+    }
+
+    /* Bump the directory offset */
+    dir->off += count;
+
+    /* Parse the buffer for the filename and file type */
+    i = 0;
+    j = 0;
+    s = 0;
+    b = buffer;
+    while (i < count) {
+        switch (s) {
+
+            case 0:
+                /* Searching for start of file name */
+                if (*b == '"') {
+                    s = 1;
+                }
+                break;
+
+            case 1:
+                /* Within file name */
+                if (*b == '"') {
+                    entry.d_name[j] = '\0';
+                    entry.d_namlen = j;
+                    s = 2;
+                } else if (j < sizeof (entry.d_name) - 1) {
+                    entry.d_name[j] = *b;
+                    ++j;
+                }
+                break;
+
+            case 2:
+                /* Searching for file type */
+                if (*b != ' ') {
+                    entry.d_type = _cbm_filetype (*b);
+                    if (*b == 'd') {
+                        /* May be DEL or DIR, check next char */
+                        s = 3;
+                    } else {
+                        /* Done */
+                        return &entry;
+                    }
+                }
+                break;
+
+            case 3:
+                /* Distinguish DEL or DIR file type entries */
+                switch (*b) {
+                    case 'e':                                   break;
+                    case 'i': entry.d_type = CBM_T_DIR;         break;
+                    default:  entry.d_type = CBM_T_OTHER;       break;
+                }
+                return &entry;
+        }
+        ++i;
+        ++b;
+    }
+
+    /* Something went wrong - terminating quote not found */
+error:
+    _errno = EIO;
+exit:
+    return 0;
+}
+
+
+