Added directory functions to the Commodore Platform File System.

They reduce the Telnet server's run size by 1231 bytes.

platform/c64/lib/pfs-dir.c

@@ -0,0 +1,171 @@
+/*
+ * Copyright (c) 2016, Greg King
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions, and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above
+ *    copyright notice, this list of conditions, and the following
+ *    disclaimer, in the documentation and/or other materials provided
+ *    with the distribution.
+ * 3. The name of the author may not be used to endorse or promote
+ *    products derived from this software without specific prior
+ *    written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR "AS IS"; AND, ANY EXPRESS
+ * OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
+ * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * This file is a part of the Contiki operating system.
+ */
+
+/*
+** Open a directory listing, so that it can be read by pfs_readdir().
+**
+** Read one file-name from a directory listing that was opened by pfs_opendir().
+**
+** 2012-05-30, Ullrich von Bassewitz
+** 2016-04-22, Greg King
+*/
+
+#include "cfs.h"
+
+typedef struct {
+    int fd;                     /* File descriptor for a directory */
+} DIR;
+
+/*---------------------------------------------------------------------------*/
+/*
+** Read characters from the directory into the supplied buffer.
+** Return true if the read was successful, and false otherwise.
+*/
+extern unsigned char __fastcall__ _pfs_dirread(struct cfs_dir *dir, void *buf,
+                                               unsigned char count);
+
+/*
+** Read one byte from the directory into the supplied buffer.
+** Return true if the read was successful, and false otherwise.
+*/
+extern unsigned char __fastcall__ _pfs_dirread1(struct cfs_dir *dir, void *buf);
+/*---------------------------------------------------------------------------*/
+int __fastcall__
+pfs_opendir(struct cfs_dir *dirp, register const char *name)
+{
+  static int fd;
+  static char buf[2 + 1] = "$";
+
+  /* Set up the actual file name that is sent to the DOS.
+  ** We accept "0:", "1:", "/", and "." as directory names.
+  */
+  if(name == NULL || name[0] == '\0' || (name[0] == '.' || name[0] == '/') && name[1] == '\0') {
+    buf[1] = '\0';
+  } else if((name[0] == '0' || name[0] == '1') && name[1] == ':' && name[2] == '\0') {
+    buf[1] = name[0];
+    buf[2] = '\0';
+  } else {
+    return -1;
+  }
+
+  /* Open the directory on a disk, for reading. */
+  fd = pfs_open(buf, CFS_READ);
+  if(fd >= 0) {
+    ((DIR *)dirp)->fd = fd;
+
+    /* Skip the load address. */
+    if(_pfs_dirread(dirp, buf + 1, 2)) {
+      return 0;
+    } else {
+      pfs_close(fd);
+    }
+  }
+
+  return -1;
+}
+/*---------------------------------------------------------------------------*/
+int __fastcall__
+pfs_readdir(struct cfs_dir *dirp, register struct cfs_dirent *dirent)
+{
+  register unsigned char *b;
+  register unsigned char i;
+  register unsigned char count;
+  unsigned char buffer[0x40];
+  static unsigned char s;
+  static unsigned char j;
+
+  /* Skip the BASIC line-link. */
+  if(!_pfs_dirread(dirp, buffer, 2)) {
+    return -1;
+  }
+
+  /* Read the number of blocks. It's a two-byte number; but, the size is
+  ** a four-byte number. Zero the size; then, put the block number in
+  ** the first two bytes. It works because the 6502 CPU's numbers are
+  ** little-endian.
+  */
+  dirent->size = 0;
+  if(!_pfs_dirread(dirp, &dirent->size, 2)) {
+    return -1;
+  }
+
+  /* Read the next file entry into a buffer. */
+  for(count = 0, b = buffer; count < sizeof(buffer); ++b) {
+    if(!_pfs_dirread1(dirp, b)) {
+      return -1;
+    }
+    ++count;
+    if(*b == '\0') {
+      break;
+    }
+  }
+
+  /* The end of the directory was reached if the buffer contains "blocks free."
+  ** It is sufficient here to check for the leading 'b'. The buffer will have
+  ** at least one byte if we come here.
+  */
+  if(buffer[0] == 'b') {
+    return -1;
+  }
+
+  /* Parse the buffer for the file-name. */
+  b = buffer;
+  j = 0;
+  s = 0;
+  i = 0;
+  while(i < count) {
+    switch(s) {
+    case 0:
+      /* Search for the start of the file-name. */
+      if(*b == '"') {
+        s = 1;
+      }
+      break;
+    case 1:
+      /* Within the file-name. */
+      if(*b == '"') {
+        /* The end of the file-name was found. */
+        dirent->name[j] = '\0';
+        return 0;
+      } else if(j < sizeof(dirent->name) - 1) {
+        dirent->name[j] = *b;
+        ++j;
+      }
+      break;
+    }
+    ++b;
+    ++i;
+  }
+
+  /* The file-name is too long for the buffer. Return what could be read. */
+  dirent->name[j] = '\0';
+  return 0;
+}