Amiga Format CD 7/Amiga Format AFCD07 (Dec 1996, Issue 91).iso/serious/shareware/programming/ixemul-complete/ixemul/library/convert_dir.c

C/C++ Source or Header | 1996-08-13 | 5.7 KB | 206 lines

/*
 *  This file is part of ixemul.library for the Amiga.
 *  Copyright (C) 1991, 1992  Markus M. Wild
 *  Portions Copyright (C) 1994 Rafael W. Luebbert
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Library General Public
 *  License as published by the Free Software Foundation; either
 *  version 2 of the License, or (at your option) any later version.
 *
 *  This library is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *  Library General Public License for more details.
 *
 *  You should have received a copy of the GNU Library General Public
 *  License along with this library; if not, write to the Free
 *  Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#define _KERNEL
#include "ixemul.h"
#include "kprintf.h"
#include <string.h>

extern int __mread (), __mclose ();

#define BUFINCR    512

/* we're writing records that look like this to the `file' */
struct file_dir {
  long    fd_key;
  long    fd_namelen;    /* padded to even size, thus perhaps zero padded */
  char    fd_name[0];    /* fd_namelen bytes of filename */
};

struct buffer {
  u_char *buf, *bp, *bend;
  int  buf_size;
};

static int add_item(struct buffer *buf, long key, char *name)
{
  int len = strlen (name);
  struct file_dir *fd;

  if ((buf->bp + (len + 2 + sizeof (struct file_dir))) >= buf->bend)
    {
      u_char *tmp;

      tmp = krealloc (buf->buf, buf->buf_size + BUFINCR);
      if (!tmp)
        {
      ix_warning("ixemul.library: out of memory!");
      kfree (buf->buf);
      errno = ENOMEM;
      return -1;
    }

      buf->buf_size += BUFINCR;
      buf->bp = tmp + (buf->bp - buf->buf);
      buf->buf = tmp;
      buf->bend = tmp + buf->buf_size;
    }

  fd = (struct file_dir *)buf->bp;
  fd->fd_key = key;
  fd->fd_namelen = len;
  /* watch out for mc68000: don't let bp ever get odd ! */
  if (fd->fd_namelen & 1)
    /* in that case zero pad the name */
    fd->fd_name[fd->fd_namelen++] = 0;

  bcopy (name, fd->fd_name, len);
  buf->bp += fd->fd_namelen + sizeof (struct file_dir);
  return 0;
}

/*
 * Convert a directory into a DTYPE_MEM file.
 *
 * NOTE: function assumes:
 *     o f is allocated and locked, it's packet is initialized
 *       o name is an existing directory (S_IFDIR from a previous stat)
 *     o signals are blocked (important! convert_dir() doesn't block them!)
 */

char *convert_dir (struct file *f, char *name, int omask)
{
  BPTR lock;
  struct buffer buf;
  struct FileInfoBlock *fib;
  int rc0;
  char pathname[1024];

  fib = alloca (sizeof (*fib) + 2);
  fib = LONG_ALIGN (fib);

  buf.buf = buf.bp = buf.bend = NULL;
  buf.buf_size = 0;
  lock = __lock (name, ACCESS_READ);
  if (lock == 0 && IoErr() == 6262)  /* root directory */
    {
      struct DosList *dl;
      int i = 3;

      /* put two dummy entries here.. some BSD code relies on the fact that
       * it can safely skip the first two `.' and `..' entries ;-)) */
      if (add_item(&buf, 1, "."))
        goto do_return;
      if (add_item(&buf, 2, ".."))
        goto do_return;

      dl = LockDosList(LDF_VOLUMES | LDF_READ);
      while ((dl = NextDosEntry(dl, LDF_VOLUMES)))
        {
          char name[256];
          u_char *s = BTOCPTR(dl->dol_Name);

          memcpy(name, s + 1, *s);
          name[*s] = 0;
          if (add_item(&buf, i++, name))
            break;
        }
      UnLockDosList(LDF_VOLUMES | LDF_READ);
      if (dl)
        goto do_return;
      strcpy(pathname, "/");
      goto read_directory;
    }
  else if (lock > 0)
    {
      rc0 = Examine (lock, fib);
      NameFromLock(lock, pathname, sizeof(pathname));

      /* put two dummy entries here.. some BSD code relies on the fact that
       * it can safely skip the first two `.' and `..' entries ;-)) */
      if (add_item(&buf, 1, "."))
        goto do_return;
      if (add_item(&buf, 2, ".."))
        goto do_return;

      /* don't include the dir-information into the file, *ix doesn't either. */
      if (rc0 == -1)
    for (;;)
      {
        /* allow for a clean abort out of a very long directory scan */
        if (u.p_sig & ~omask)
          {
        /* if a signal is pending that was not blocked before entry to
         * open(), break here and return with EINTR */
        errno = EINTR;
        kfree (buf.buf);
        goto do_return;
          }

        rc0 = ExNext (lock, fib);

            if (rc0 != -1)
          break;

            if (add_item(&buf, (long)((struct FileLock *)(BTOCPTR(lock)))->fl_Key,
                         fib->fib_FileName))
              goto do_return;
      }

read_directory:
      /* fine.. fill out the memory file object */
      f->f_type        = DTYPE_MEM;
      f->f_mf.mf_offset = 0;
      f->f_mf.mf_buffer = buf.buf;
      f->f_read        = __mread;
      f->f_close    = __mclose;
      f->f_ioctl    = 0;
      f->f_select    = 0;
      f->f_stb.st_size    = buf.bp - buf.buf;
      /*
       * have to use kmalloc() instead of malloc(), because this is no task-private
       * data, it could (in the future) be shared by other tasks
       */
      f->f_name = (void *)kmalloc(strlen(pathname) + 1);
      if (f->f_name)
        strcpy (f->f_name, pathname);

      /* NOTE: the rest of the stb should be ok from the previous stat() in
       *       open() */
      __unlock (lock);
      return f->f_name;
    }
  else
    {
      errno = ENOENT;
      KPRINTF (("&errno = %lx, errno = %ld\n", &errno, errno));
      return NULL;
    }

  /* NOTE: granted, this is a bit spaghetti here.. the else above guarantees that
           we won't unlock a lock we never got. So it's safe to unconditionally
           unlock at the end. */

do_return:
  __unlock (lock);
  KPRINTF (("&errno = %lx, errno = %ld\n", &errno, errno));
  return NULL;
}