Add in libutil, based on Cory Visi's variant of Michael Shmulevich's libutil

port.  I have reworked the code quite a bit so that the stuff that is supposed
to be in libc is in libc, and I added a bunch of missing stuff so the libutil
interface matches that of glibc's libutil.  The only caveat is that
libutil/login.c is currently a stub.
 -Erik

1 files changed, 171 insertions, 0 deletions

diff --git a/libc/stdlib/ptsname.c b/libc/stdlib/ptsname.c
new file mode 100644
index 000000000..2fbc6be49
--- /dev/null
+++ b/libc/stdlib/ptsname.c
@@ -0,0 +1,171 @@
+/* Copyright (C) 1998 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Zack Weinberg <zack@rabi.phys.columbia.edu>, 1998.
+
+   The GNU C 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.
+
+   The GNU C 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 the GNU C Library; see the file COPYING.LIB.  If not,
+   write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.  */
+
+#include <errno.h>
+#include <paths.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/ioctl.h>
+#include <sys/stat.h>
+#include <sys/sysmacros.h>
+#include <termios.h>
+#include <unistd.h>
+
+/* Check if DEV corresponds to a master pseudo terminal device.  */
+#define MASTER_P(Dev)                                                         \
+  (major ((Dev)) == 2                                                         \
+   || (major ((Dev)) == 4 && minor ((Dev)) >= 128 && minor ((Dev)) < 192)     \
+   || (major ((Dev)) >= 128 && major ((Dev)) < 136))
+
+/* Check if DEV corresponds to a master pseudo terminal device.  */
+#define SLAVE_P(Dev)                                                          \
+  (major ((Dev)) == 3                                                         \
+   || (major ((Dev)) == 4 && minor ((Dev)) >= 192 && minor ((Dev)) < 256)     \
+   || (major ((Dev)) >= 136 && major ((Dev)) < 144))
+
+/* Note that major number 4 corresponds to the old BSD style pseudo
+   terminal devices.  As of Linux 2.1.115 these are no longer
+   supported.  They have been replaced by major numbers 2 (masters)
+   and 3 (slaves).  */
+     
+/* Directory where we can find the slave pty nodes.  */
+#define _PATH_DEVPTS "/dev/pts/"
+
+/* The are declared in getpt.c.  */
+extern const char _ptyname1[];
+extern const char _ptyname2[];
+
+/* Static buffer for `ptsname'.  */
+static char buffer[sizeof (_PATH_DEVPTS) + 20];
+
+/*
+extern char * 
+_itoa_word (unsigned long value, char *buflim,
+	unsigned int base, int upper_case);
+*/
+
+
+/* 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)
+{
+  int save_errno = errno;
+  struct stat st;
+  int ptyno;
+
+  if (buf == NULL)
+    {
+      errno = EINVAL;
+      return EINVAL;
+    }
+
+  if (!isatty (fd))
+    {
+      errno = ENOTTY;
+      return ENOTTY;
+    }
+#if 0
+#ifdef TIOCGPTN
+  if (ioctl (fd, TIOCGPTN, &ptyno) == 0)
+    {
+      /* Buffer we use to print the number in.  For a maximum size for
+         `int' of 8 bytes we never need more than 20 digits.  */
+      char numbuf[21];
+      const char *devpts = _PATH_DEVPTS;
+      const size_t devptslen = strlen (devpts);
+      char *p;
+
+      numbuf[20] = '\0';
+      p = _itoa_word (ptyno, &numbuf[20], 10, 0);
+
+      if (buflen < devptslen + strlen (p) + 1)
+	{
+	  errno = ERANGE;
+	  return ERANGE;
+	}
+
+      strcpy (buf, devpts);
+      strcat (buf, p);
+    }
+  else if (errno == EINVAL)
+#endif
+#endif
+    {
+      char *p;
+
+      if (buflen < strlen (_PATH_TTY) + 3)
+	{
+	  errno = ERANGE;
+	  return ERANGE;
+	}
+
+      if (fstat (fd, &st) < 0)
+	return errno;
+
+      /* Check if FD really is a master pseudo terminal.  */
+      if (! MASTER_P (st.st_rdev))
+	{
+	  errno = ENOTTY;
+	  return ENOTTY;
+	}
+
+      ptyno = minor (st.st_rdev);
+      /* This is for the old BSD pseudo terminals.  As of Linux
+         2.1.115 these are no longer supported.  */
+      if (major (st.st_rdev) == 4)
+	ptyno -= 128;
+
+      if (ptyno / 16 >= strlen (_ptyname1))
+	{
+	  errno = ENOTTY;
+	  return ENOTTY;
+	}
+
+      strcpy (buf, _PATH_TTY);
+      p = buf + strlen (buf);
+      p[0] = _ptyname1[ptyno / 16];
+      p[1] = _ptyname2[ptyno % 16];
+      p[2] = '\0';
+    }
+
+  if (_xstat (_STAT_VER, buf, &st) < 0)
+    return errno;
+
+  /* Check if the name we're about to return really corresponds to a
+     slave pseudo terminal.  */
+  if (! S_ISCHR (st.st_mode) || ! SLAVE_P (st.st_rdev))
+    {
+      /* This really is a configuration problem.  */
+      errno = ENOTTY;
+      return ENOTTY;
+    }
+
+  errno = save_errno;
+  return 0;
+}
+
+/* Return the pathname of the pseudo terminal slave assoicated with
+   the master FD is open on, or NULL on errors.
+   The returned storage is good until the next call to this function.  */
+char *
+ptsname (int fd)
+{
+  return ptsname_r (fd, buffer, sizeof (buffer)) != 0 ? NULL : buffer;
+}