/* Return the result of ptsname_r in the buffer pointed to by PTS,
which should be of length BUF_LEN. If it is too long to fit in
this buffer, a sufficiently long buffer is allocated using malloc,
and returned in PTS. 0 is returned upon success, -1 otherwise. */
static int
pts_name (int fd, char **pts, size_t buf_len, struct stat64 *stp)
{
int rv;
char *buf = *pts;
for (;;)
{
char *new_buf;
if (buf_len)
{
rv = __ptsname_internal (fd, buf, buf_len, stp);
if (rv != 0)
{
if (rv == ENOTTY)
/* ptsname_r returns with ENOTTY to indicate
a descriptor not referring to a pty master.
For this condition, grantpt must return EINVAL. */
rv = EINVAL;
errno = rv; /* Not necessarily set by __ptsname_r. */
break;
}
if (memchr (buf, '\0', buf_len))
/* We succeeded and the returned name fit in the buffer. */
break;
/* Try again with a longer buffer. */
buf_len += buf_len; /* Double it */
}
else
/* No initial buffer; start out by mallocing one. */
buf_len = 128; /* First time guess. */
if (buf != *pts)
/* We've already malloced another buffer at least once. */
new_buf = (char *) realloc (buf, buf_len);
else
new_buf = (char *) malloc (buf_len);
if (! new_buf)
{
rv = -1;
__set_errno (ENOMEM);
break;
}
buf = new_buf;
}
if (rv == 0)
*pts = buf; /* Return buffer to the user. */
else if (buf != *pts)
free (buf); /* Free what we malloced when returning an error. */
return rv;
}
/* Store at most BUFLEN characters of the pathname of the slave pseudo
terminal associated with the master FD is open on in BUF.
Return 0 on success, otherwise an error number. */
int
__ptsname_r (int fd, char *buf, size_t buflen)
{
struct stat64 st;
return __ptsname_internal (fd, buf, buflen, &st);
}
