Re: coreutils-6.0: numerous test failures on MacOS X

[Paul Eggert]

Bruno Haible <address@hidden> writes:

> The process that hangs has the command line "tail -f -n 1".

I installed the following patch to coreutils in an attempt to fix
this.  It uses the new isapipe module of gnulib.  I think this
finishes off the MacOS X problems you've reported recently.

2006-08-29  Paul Eggert  <address@hidden>

        * bootstrap.conf (gnulib_modules): Add isapipe.
        * src/tail.c: Include isapipe.h.
        (IS_PIPE_LIKE_FILE_TYPE): Remove.
        (IS_TAILABLE_FILE_TYPE): Just list both FIFOs and sockets as
        tailable, since this seems to be portable.
        (main): Use isapipe, to fix a bug on MacOS X reported by Bruno Haible in
        <http://lists.gnu.org/archive/html/bug-coreutils/2006-08/msg00304.html>.

--- bootstrap.conf      28 Aug 2006 23:05:13 -0000      1.7
+++ bootstrap.conf      29 Aug 2006 20:47:24 -0000
@@ -47,7 +47,8 @@ gnulib_modules="
        getline getloadavg getndelim2 getopt getpagesize getpass-gnu
        gettext gettime gettimeofday getugroups getusershell gnupload
        group-member hard-locale hash hash-pjw host-os human idcache
-       inttostr inttypes lchmod lchown lib-ignore linebuffer link-follow
+       inttostr inttypes isapipe
+       lchmod lchown lib-ignore linebuffer link-follow
        long-options lstat malloc mbswidth md5 memcasecmp mempcpy
        memrchr mkancesdirs mkdir mkdir-p mkstemp mktime modechange
        mountlist obstack pathmax perl physmem posixtm posixver putenv
--- src/tail.c  1 Jul 2006 23:50:15 -0000       1.250
+++ src/tail.c  29 Aug 2006 20:47:25 -0000
@@ -37,6 +37,7 @@
 #include "error.h"
 #include "fcntl--.h"
 #include "inttostr.h"
+#include "isapipe.h"
 #include "posixver.h"
 #include "quote.h"
 #include "safe-read.h"
@@ -74,14 +75,9 @@ enum Follow_mode
   Follow_descriptor = 2
 };
 
-/* On Darwin 7.7, when reading from a command-line pipe, standard
-   input is of type S_ISSOCK.  Everywhere else it's S_ISFIFO.  */
-#define IS_PIPE_LIKE_FILE_TYPE(Mode) \
-  (S_ISFIFO (Mode) || S_ISSOCK (Mode))
-
 /* The types of files for which tail works.  */
 #define IS_TAILABLE_FILE_TYPE(Mode) \
-  (S_ISREG (Mode) || IS_PIPE_LIKE_FILE_TYPE (Mode) || S_ISCHR (Mode))
+  (S_ISREG (Mode) || S_ISFIFO (Mode) || S_ISSOCK (Mode) || S_ISCHR (Mode))
 
 static char const *const follow_mode_string[] =
 {
@@ -1640,14 +1636,14 @@ main (int argc, char **argv)
         device type, because device independence is an important
         principle of the system's design.
 
-        Follow the POSIX requirement only if POSIXLY_CORRECT is set.
-        Ideally this would ignore -f only for pipes, but S_ISFIFO
-        succeeds for both FIFOs and pipes and we know of no portable,
-        reliable way to distinguish them.  */
+        Follow the POSIX requirement only if POSIXLY_CORRECT is set.  */
+
       if (forever && getenv ("POSIXLY_CORRECT"))
        {
-         struct stat stats;
-         if (fstat (STDIN_FILENO, &stats) == 0 && S_ISFIFO (stats.st_mode))
+         int is_a_pipe = isapipe (STDIN_FILENO);
+         if (is_a_pipe < 0)
+           error (EXIT_FAILURE, errno, _("standard input"));
+         if (is_a_pipe)
            forever = false;
        }
     }