/* tmpfile.c (emx+gcc) -- Copyright (c) 1990-1993 by Eberhard Mattes */
/*                        Copyright (c) 1991-1993 by Kolja Elsaesser */

#include <sys/emx.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <io.h>
#include <errno.h>
#include <sys/param.h>

#define IDX_LO 10000000
#define IDX_HI 99999999

static int _tmpidx = IDX_LO;

static int _isdir (char *dst, const char *src);


FILE *tmpfile (void)
{
  char name[L_tmpnam];
  FILE *f;

  if (tmpnam (name) == NULL)
    return (NULL);
  f = fopen (name, "w+b");
  if (f == NULL)
    return (NULL);
  f->tmpidx = _tmpidx;
  f->flags |= _IOTMP;
  return (f);
}


char *tmpnam (char *string)
{
  char *p;
  int saved_errno, idx_start;
#if defined (__MT__)
  struct _thread *tp = _thread ();
#define tnbuf (tp->_th_tmpnam_buf)
#else
  static char tnbuf[L_tmpnam];
#endif

  if (string == NULL) string = tnbuf;
  strcpy (string, P_tmpdir);
  p = strchr (string, 0);
  if (string[0] != 0 && p[-1] != '\\' && p[-1] != '/' && p[-1] != ':')
    *p++ = '/';
  saved_errno = errno;
  idx_start = _tmpidx;
  for (;;)
    {
      if (_tmpidx >= IDX_HI)
        _tmpidx = IDX_LO;
      else
        ++_tmpidx;
      if (_tmpidx == idx_start)
        {
          errno = EINVAL;
          return (NULL);
        }
      _itoa (_tmpidx, p, 10);
      strcat (p, ".tmp");
      errno = 0;
      if (access (string, 0) != 0)
        {
          if (errno == ENOENT)
            break;
          return (NULL);
        }
    }
  errno = saved_errno;
  return (string);
}

/* Create absolute path name from src, copy it to dst and return 1 if
   it's a directory. Note that this works also with a trailing backslash! */

static int _isdir (char *dst, const char *src)
{
  int attr;

  if (_fullpath (dst, src, MAXPATHLEN) != 0)
    return (0);
  attr = __chmod (dst, 0, 0);
  return (attr >= 0 && (attr & _A_SUBDIR));
}


char *tempnam (const char *dir, const char *prefix)
{
  const char *tmpdir;
  char *tmpname, *p, buf[MAXPATHLEN];
  int saved_errno, idx_start;

  saved_errno = errno;
  if (strlen (prefix) > 5)
    {
      errno = EINVAL;
      return (NULL);
    }
  tmpdir = NULL;
  p = getenv ("TMP");
  if (tmpdir == NULL && p != NULL && _isdir (buf, p))
    tmpdir = buf;
  if (tmpdir == NULL && dir != NULL && _isdir (buf, dir))
    tmpdir = buf;
  if (tmpdir == NULL)
    tmpdir = P_tmpdir;
  tmpname = malloc (strlen (tmpdir) + 1 + L_tmpnam);
  if (tmpname == NULL)
    {
      errno = ENOMEM;
      return (NULL);
    }
  strcpy (tmpname, tmpdir);
  p = strchr (tmpname, 0);
  if (tmpname[0] != 0 && p[-1] != '\\' && p[-1] != '/' && p[-1] != ':')
    *p++ = '/';
  idx_start = _tmpidx;
  for (;;)
    {
      if (_tmpidx == IDX_HI)
        _tmpidx = IDX_LO;
      else
        ++_tmpidx;
      if (_tmpidx == idx_start)
        {
          free (tmpname);
          errno = EINVAL;
          return (NULL);
        }
      _itoa (_tmpidx, p, 10);
      strcat (p, ".tmp");
      memmove (p, prefix, strlen (prefix));
      errno = 0;
      if (access (tmpname, 0) != 0)
        {
          if (errno == ENOENT)
            break;
          return (NULL);
        }
    }
  errno = saved_errno;
  if (_fullpath (buf, tmpname, sizeof (buf)) != 0)
    {
      free (tmpname);
      errno = ENOENT;
      return (NULL);
    }
  free (tmpname);
  p = strdup (buf);
  if (p == NULL)
    errno = ENOMEM;
  return (p);
}