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Re: HOST_NAME_MAX
From: |
Simon Josefsson |
Subject: |
Re: HOST_NAME_MAX |
Date: |
Wed, 01 Apr 2009 13:54:04 +0200 |
User-agent: |
Gnus/5.110011 (No Gnus v0.11) Emacs/23.0.90 (gnu/linux) |
Bruno Haible <address@hidden> writes:
>> One complication is that POSIX says the symbol should be defined in
>> limits.h. Do we need a gnulib replacement header for limits.h to be
>> able to define HOST_NAME_MAX?
>
> No, it is more convenient to define it in config.h, simply through
> AC_DEFINE.
...
> The definition can be triggered by the 'gethostname' module. I don't think
> anyone will need HOST_NAME_MAX without needing the gethostname() function.
That would be fine with me. How about the patch below? This is on top
of my earlier gethostname patch for mingw.
/Simon
diff --git a/doc/posix-headers/limits.texi b/doc/posix-headers/limits.texi
index 0b5e431..d404b9c 100644
--- a/doc/posix-headers/limits.texi
+++ b/doc/posix-headers/limits.texi
@@ -11,4 +11,7 @@ Portability problems fixed by Gnulib:
Portability problems not fixed by Gnulib:
@itemize
+The @code{HOST_NAME_MAX} symbol is not defined under Windows, use the
address@hidden gnulib module to get it.
+
@end itemize
diff --git a/m4/gethostname.m4 b/m4/gethostname.m4
index 620e023..a2b8e60 100644
--- a/m4/gethostname.m4
+++ b/m4/gethostname.m4
@@ -42,7 +42,13 @@ AC_DEFUN([gl_FUNC_GETHOSTNAME],
# Prerequisites of lib/gethostname.c.
AC_DEFUN([gl_PREREQ_GETHOSTNAME], [
- if test "$gl_cv_w32_gethostname" != "yes"; then
+ if test "$gl_cv_w32_gethostname" = "yes"; then
+ # <http://msdn.microsoft.com/en-us/library/ms738527.aspx> says:
+ # "if a buffer of 256 bytes is passed in the name parameter and
+ # the namelen parameter is set to 256, the buffer size will always
+ # be adequate."
+ AC_DEFINE([HOST_NAME_MAX], [256], [Define HOST_NAME_MAX on Mingw.])
+ else
AC_CHECK_FUNCS([uname])
fi
])
diff --git a/modules/gethostname b/modules/gethostname
index e21afe6..a50c22b 100644
--- a/modules/gethostname
+++ b/modules/gethostname
@@ -1,5 +1,5 @@
Description:
-gethostname() function: Return machine's hostname.
+Provide HOST_NAME_MAX and gethostname() function: Return machine's hostname.
Files:
lib/gethostname.c
diff --git a/tests/test-gethostname.c b/tests/test-gethostname.c
index ef50953..c1914fd 100644
--- a/tests/test-gethostname.c
+++ b/tests/test-gethostname.c
@@ -1,5 +1,5 @@
/*
- * Copyright (C) 2008 Free Software Foundation
+ * Copyright (C) 2008, 2009 Free Software Foundation
* Written by Simon Josefsson.
*
* This program is free software: you can redistribute it and/or modify
@@ -28,9 +28,15 @@
int
main (int argc, char *argv[])
{
- char buf[2500];
+ char buf[HOST_NAME_MAX];
int rc;
+ if (strlen (NOHOSTNAME) >= HOST_NAME_MAX)
+ {
+ printf ("HOST_NAME_MAX impossibly small?! %d\n", HOST_NAME_MAX);
+ return 2;
+ }
+
strcpy (buf, NOHOSTNAME);
rc = gethostname (buf, sizeof (buf));