ptsname_r on OSF/1

[Bruno Haible]

On OSF/1, gnulib's ptsname_r function returns a file name like
"/dev/ttyp5". But ptsname() returns something like "/dev/pts/5".
How does it do this? 'truss' reveals it:

  ioctl(3, 0x20007447, 0x00000000)                = 7340037 = 0x700005
  stat("/dev/pts/5", 0x000000011FFFBA70)          = 0

To make ptsname_r() consistent with ptsname(), I'm therefore adding this
patch:


2012-06-24  Bruno Haible  <bruno@...>

        ptsname_r: Make it consistent with ptsname on OSF/1.
        * lib/ptsname_r.c (__ptsname_r): Add a different implementation for
        OSF/1.

--- lib/ptsname_r.c.orig Sun Jun 24 23:24:44 2012
+++ lib/ptsname_r.c Sun Jun 24 23:23:10 2012
@@ -53,6 +53,14 @@
 # include <stdio.h>
 #endif
 
+#ifdef __osf__
+/* Get ioctl(), ISPTM.  */
+# include <sys/ioctl.h>
+/* Get the major, minor macros.  */
+# include <sys/sysmacros.h>
+# include <stdio.h>
+#endif
+
 
 /* Store at most BUFLEN characters of the pathname of the slave pseudo
    terminal associated with the master FD is open on in BUF.
@@ -103,6 +111,35 @@
     if (n >= buflen)
       {
         errno = ERANGE;
+        return errno;
+      }
+    memcpy (buf, tmpbuf, n + 1);
+  }
+#elif defined __osf__ /* OSF/1 */
+  /* This implementation returns /dev/pts/N, like ptsname() does.
+     Whereas the generic implementation below returns /dev/ttypN.
+     Both are correct, but let's be consistent with ptsname().  */
+  if (fstat (fd, &st) < 0)
+    return errno;
+  if (!S_ISCHR (st.st_mode))
+    {
+      errno = ENOTTY;
+      return errno;
+    }
+  {
+    int dev;
+    char tmpbuf[9 + 10 + 1];
+    int n;
+    dev = ioctl (fd, ISPTM, NULL);
+    if (dev < 0)
+      {
+        errno = ENOTTY;
+        return errno;
+      }
+    n = sprintf (tmpbuf, "/dev/pts/%u", minor (dev));
+    if (n >= buflen)
+      {
+        errno = ERANGE;
         return errno;
       }
     memcpy (buf, tmpbuf, n + 1);

[Bruno Haible]

> 2012-06-24  Bruno Haible  <bruno@...>
>
> ptsname_r: Make it consistent with ptsname on OSF/1.
> * lib/ptsname_r.c (__ptsname_r): Add a different implementation for
> OSF/1.

Nearly the same code works also on AIX. Unfortunately, it does not fix
the problem that close() hangs when applied to the pty master's fd. Add
a comment about it in the test.


2012-06-24  Bruno Haible  <bruno@...>

        ptsname_r: Make it consistent with ptsname on AIX.
        * lib/ptsname_r.c (__ptsname_r): For AIX, use nearly the same
        implementation as for OSF/1.
        * tests/test-ptsname_r.c (main) [AIX]: Use the modern way of opening
        a pty master.

--- lib/ptsname_r.c.orig Mon Jun 25 00:58:44 2012
+++ lib/ptsname_r.c Mon Jun 25 00:40:19 2012
@@ -53,7 +53,7 @@
 # include <stdio.h>
 #endif
 
-#ifdef __osf__
+#if defined _AIX || defined __osf__
 /* Get ioctl(), ISPTM.  */
 # include <sys/ioctl.h>
 /* Get the major, minor macros.  */
@@ -115,7 +115,7 @@
       }
     memcpy (buf, tmpbuf, n + 1);
   }
-#elif defined __osf__ /* OSF/1 */
+#elif defined _AIX || defined __osf__ /* AIX, OSF/1 */
   /* This implementation returns /dev/pts/N, like ptsname() does.
      Whereas the generic implementation below returns /dev/ttypN.
      Both are correct, but let's be consistent with ptsname().  */
@@ -127,10 +127,17 @@
       return errno;
     }
   {
+    int ret;
     int dev;
     char tmpbuf[9 + 10 + 1];
     int n;
-    dev = ioctl (fd, ISPTM, NULL);
+# ifdef _AIX
+    ret = ioctl (fd, ISPTM, &dev);
+# endif
+# ifdef __osf__
+    ret = ioctl (fd, ISPTM, NULL);
+    dev = ret;
+# endif
     if (dev < 0)
       {
         errno = ENOTTY;
--- tests/test-ptsname_r.c.orig Mon Jun 25 00:58:44 2012
+++ tests/test-ptsname_r.c Mon Jun 25 00:42:36 2012
@@ -151,7 +151,7 @@
     char buffer[256];
     int result;
 
-    /* Open the controlling tty of the current process.  */
+    /* Open a pty master.  */
     fd = open ("/dev/ptmx", O_RDWR | O_NOCTTY);
     if (fd < 0)
       {
@@ -168,6 +168,32 @@
     close (fd);
   }
 
+#elif defined _AIX
+  /* AIX has BSD-style /dev/ptyp[0-9a-f] files, but the modern way to open
+     a pty is to go through /dev/ptc.  */
+  {
+    int fd;
+    char buffer[256];
+    int result;
+
+    /* Open a pty master.  */
+    fd = open ("/dev/ptc", O_RDWR | O_NOCTTY);
+    if (fd < 0)
+      {
+        fprintf (stderr, "Skipping test: cannot open pseudo-terminal\n");
+        return 77;
+      }
+
+    result = ptsname_r (fd, buffer, sizeof buffer);
+    ASSERT (result == 0);
+    ASSERT (memcmp (buffer, "/dev/pts/", 9) == 0);
+
+    test_errors (fd, buffer);
+
+    /* This call hangs on AIX.  */
+    close (fd);
+  }
+
 #else
 
   /* Try various master names of Mac OS X: /dev/pty[p-w][0-9a-f]  */
@@ -196,6 +222,7 @@
 
               test_errors (fd, buffer);
 
+              /* This call hangs on AIX.  */
               close (fd);
             }
         }