/*
 * This routine is derived from BSD4.3 code,
 * Copyright (c) 1988 Regents of the University of California.
 * All rights reserved.
 */
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)tmpnam.c	4.5 (Berkeley) 6/27/88";
#endif /* LIBC_SCCS and not lint */
/*----------------------------------------------------------------------
      Return a unique file name in a given directory.  This is not quite
      the same as the usual tempnam() function, though it is very similar.
      We want it to use the TMP environment variable only if dir is NULL,
      instead of using TMP regardless if it is set.

  Args: dir      -- The directory to create the name in
        prefix   -- Prefix of the name
 
 Result: Malloc'd string equal to new name is returned.  It must be free'd
	 by the caller.  Returns the string on success and NULL on failure.
  ----*/
char *
temp_nam(dir, prefix)
    char *dir, *prefix;
{
    struct stat buf;
    char *f, *name;
    char *our_mktemp();

    if (!(name = malloc((unsigned int)MAXPATHLEN)))
        return((char *)NULL);

    if (!dir && (f = getenv("TMPDIR")) && !stat(f, &buf) &&
                         (buf.st_mode&S_IFMT) == S_IFDIR &&
			 !can_access(f, WRITE_ACCESS|EXECUTE_ACCESS)) {
        (void)strcpy(name, f);
        goto done;
    }

    if (dir && !stat(dir, &buf) &&
                         (buf.st_mode&S_IFMT) == S_IFDIR &&
	                 !can_access(dir, WRITE_ACCESS|EXECUTE_ACCESS)) {
        (void)strcpy(name, dir);
        goto done;
    }

#ifndef P_tmpdir
#define	P_tmpdir	"/usr/tmp"
#endif
    if (!stat(P_tmpdir, &buf) &&
                         (buf.st_mode&S_IFMT) == S_IFDIR &&
			 !can_access(P_tmpdir, WRITE_ACCESS|EXECUTE_ACCESS)) {
        (void)strcpy(name, P_tmpdir);
        goto done;
    }

    if (!stat("/tmp", &buf) &&
                         (buf.st_mode&S_IFMT) == S_IFDIR &&
			 !can_access("/tmp", WRITE_ACCESS|EXECUTE_ACCESS)) {
        (void)strcpy(name, "/tmp");
        goto done;
    }
    return((char *)NULL);

done:
    (void)strcat(name, "/");

    if (prefix)
        (void)strcat(name, prefix);
    (void)strcat(name, "XXXXXX");
    return(our_mktemp(name));
}


/*
 * This routine is derived from BSD4.3 code,
 * Copyright (c) 1987 Regents of the University of California.
 * All rights reserved.
 *
 * We use this instead of mktemp() since we know of at least one stupid
 * mktemp() (AIX3.2) which breaks things.
 */
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)mktemp.c	5.7 (Berkeley) 6/27/88";
#endif /* LIBC_SCCS and not lint */

static
_gettemp(as)
	char	*as;
{
	extern int	errno;
	register char	*start, *trv;
	struct stat	sbuf;
	u_int	pid;

	pid = getpid();

	/* extra X's get set to 0's */
	for (trv = as; *trv; ++trv);
	while (*--trv == 'X') {
		*trv = (pid % 10) + '0';
		pid /= 10;
	}

	/*
	 * check for write permission on target directory; if you have
	 * six X's and you can't write the directory, this will run for
	 * a *very* long time.
	 */
	for (start = ++trv; trv > as && *trv != '/'; --trv);
	if (*trv == '/') {
		*trv = '\0';
		if (stat(as, &sbuf) || !(sbuf.st_mode & S_IFDIR))
			return(0);
		*trv = '/';
	}
	else if (stat(".", &sbuf) == -1)
		return(0);

	for (;;) {
		if (stat(as, &sbuf))
			return(errno == ENOENT ? 1 : 0);

		/* tricky little algorithm for backward compatibility */
		for (trv = start;;) {
			if (!*trv)
				return(0);
			if (*trv == 'z')
				*trv++ = 'a';
			else {
				if (isdigit(*trv))
					*trv = 'a';
				else
					++*trv;
				break;
			}
		}
	}
	/*NOTREACHED*/
}

char *
our_mktemp(as)
	char	*as;
{
	return(_gettemp(as) ? as : (char *)NULL);
}


