/* Open an available pty, returning a file descriptor.
Return -1 on failure. */
s48_ref_t allocate_pty(s48_call_t call) {
/* Unix98 standardized grantpt, unlockpt, and ptsname, but not the
functions required to open a master pty in the first place :-(
Modern Unix systems all seems to have convenience methods to open
a master pty fd in one function call, but there is little
agreement on how to do it.
allocate_pty() tries all the different known easy ways of opening
a pty. In case of failure, we resort to the old BSD-style pty
grovelling code in allocate_pty_the_old_fashioned_way(). */
int master_fd = -1;
const char *slave_name = NULL;
const char* clone = NULL;
int off = 0;
s48_ref_t scm_slave_name = s48_unspecific_2(call);
master_fd = allocate_master(&slave_name, &clone);
if (master_fd == -1)
return s48_false_2(call);
if (slave_name == NULL){
slave_name = allocate_slave_name(master_fd, clone);
if (slave_name == NULL){
retry_close (master_fd);
return s48_false_2(call);
}
}
scm_slave_name = s48_enter_byte_string_2(call, (char *) slave_name);
#ifdef TIOCPKT
/* In some systems (Linux through 2.0.0, at least), packet mode doesn't
get cleared when a pty is closed, so we need to clear it here.
Linux pre2.0.13 contained an attempted fix for this (from Ted Ts'o,
[email protected]), but apparently it messed up rlogind and telnetd, so he
removed the fix in pre2.0.14. - [email protected]
*/
ioctl (master_fd, TIOCPKT, (char *)&off);
#endif /* TIOCPKT */
/* We jump through some hoops to frob the pty.
It's not obvious that checking the return code here is useful. */
/* "The grantpt() function will fail if it is unable to successfully
invoke the setuid root program. It may also fail if the
application has installed a signal handler to catch SIGCHLD
signals." */
#if defined (HAVE_GRANTPT) || defined (HAVE_UNLOCKPT)
BLOCK_SIGNAL (SIGCHLD);
#if defined (HAVE_GRANTPT)
grantpt (master_fd);
#endif /* HAVE_GRANTPT */
#if defined (HAVE_UNLOCKPT)
unlockpt (master_fd);
#endif
UNBLOCK_SIGNAL (SIGCHLD);
#endif /* HAVE_GRANTPT || HAVE_UNLOCKPT */
fcntl(master_fd, F_SETFL, O_NONBLOCK);
return s48_cons_2(call, s48_enter_long_2(call, master_fd), scm_slave_name);
}
static int allocate_master(const char ** slave_name, const char** clone) {
int master_fd = -1;
static const char * const clones[] =
/* Different pty master clone devices */
{
"/dev/ptmx", /* Various systems */
"/dev/ptm/clone", /* HPUX */
"/dev/ptc", /* AIX */
"/dev/ptmx_bsd" /* Tru64 */
};
#ifdef HAVE_GETPT /* glibc */
master_fd = getpt ();
if (master_fd >= 0)
return master_fd;
#endif /* HAVE_GETPT */
#if defined(HAVE_OPENPTY) /* BSD, Tru64, glibc */
{
int slave_fd = -1;
int rc;
BLOCK_SIGNAL (SIGCHLD);
rc = openpty (&master_fd, &slave_fd, NULL, NULL, NULL);
UNBLOCK_SIGNAL (SIGCHLD);
if (rc == 0)
{
*slave_name = ttyname (slave_fd);
retry_close (slave_fd);
return master_fd;
}
else
{
if (master_fd >= 0)
retry_close (master_fd);
if (slave_fd >= 0)
retry_close (slave_fd);
}
}
#endif /* HAVE_OPENPTY */
#if defined(HAVE__GETPTY) && defined (O_NDELAY) /* SGI */
master_fd = -1;
BLOCK_SIGNAL (SIGCHLD);
*slave_name = _getpty (&master_fd, O_RDWR | O_NDELAY, 0600, 0);
UNBLOCK_SIGNAL (SIGCHLD);
if (master_fd >= 0 && *slave_name != NULL)
return master_fd;
#endif /* HAVE__GETPTY */
/* Master clone devices are available on most systems */
{
int i;
for (i = 0; i < countof (clones); i++)
{
*clone = clones[i];
master_fd = open ((char *) *clone, // TODO: retry open
O_RDWR | O_NONBLOCK, 0);
if (master_fd >= 0)
return master_fd;
}
*clone = NULL;
}
return -1;
}
static Lisp_Object
get_object_file_name (Lisp_Object filepos)
{
REGISTER int fd;
REGISTER Ibyte *name_nonreloc = 0;
EMACS_INT position;
Lisp_Object file, tem;
Lisp_Object name_reloc = Qnil;
int standard_doc_file = 0;
if (FIXNUMP (filepos))
{
file = Vinternal_doc_file_name;
standard_doc_file = 1;
position = XFIXNUM (filepos);
}
else if (CONSP (filepos) && FIXNUMP (XCDR (filepos)))
{
file = XCAR (filepos);
position = XFIXNUM (XCDR (filepos));
if (position < 0)
position = - position;
}
else
return Qnil;
if (!STRINGP (file))
return Qnil;
/* Put the file name in NAME as a C string.
If it is relative, combine it with Vdoc_directory. */
tem = Ffile_name_absolute_p (file);
if (NILP (tem))
{
Bytecount minsize;
/* XEmacs: Move this check here. OK if called during loadup to
load byte code instructions. */
if (!STRINGP (Vdoc_directory))
return Qnil;
minsize = XSTRING_LENGTH (Vdoc_directory);
/* sizeof ("../lib-src/") == 12 */
if (minsize < 12)
minsize = 12;
name_nonreloc = alloca_ibytes (minsize + XSTRING_LENGTH (file) + 8);
string_join (name_nonreloc, Vdoc_directory, file);
}
else
name_reloc = file;
fd = qxe_open (name_nonreloc ? name_nonreloc :
XSTRING_DATA (name_reloc), O_RDONLY | OPEN_BINARY, 0);
if (fd < 0)
{
if (purify_flag)
{
/* sizeof ("../lib-src/") == 12 */
name_nonreloc = alloca_ibytes (12 + XSTRING_LENGTH (file) + 8);
/* Preparing to dump; DOC file is probably not installed.
So check in ../lib-src. */
qxestrcpy_ascii (name_nonreloc, "../lib-src/");
qxestrcat (name_nonreloc, XSTRING_DATA (file));
fd = qxe_open (name_nonreloc, O_RDONLY | OPEN_BINARY, 0);
}
if (fd < 0)
report_file_error ("Cannot open doc string file",
name_nonreloc ? build_istring (name_nonreloc) :
name_reloc);
}
tem = extract_object_file_name (fd, position, name_nonreloc, name_reloc,
standard_doc_file);
retry_close (fd);
if (!STRINGP (tem))
signal_error_1 (Qinvalid_byte_code, tem);
return tem;
}
