Simon Josefsson wrote:
> > I'm undecided.
>
> Avoiding -lws2_32 is good, but if the application links to -lws2_32
> anyway, there will be no saving.
> ...
> Some additional questions:
>
> 1) How do I use it? This doesn't seem to work:
>
> j...@mocca:~$ cat foo.c
> #define WINVER 0x0500
> #include <windows.h>
> #include <stdio.h>
> int main () {
> char out[1024];
> DWORD size = 1024;
> BOOL t = GetComputerNameEx(ComputerNameDnsHostname, out, &size);
> printf("hi %d: %s", t, out);
> }
> j...@mocca:~$ i586-mingw32msvc-gcc -o foo.exe foo.c
> /tmp/ccDXn2yi.o:foo.c:(.text+0x37): undefined reference to
> `_GetComputerNameEx'
> collect2: ld returned 1 exit status
> j...@mocca:~$
>
> 2) What is the maximum string size that GetComputerNameEx can return?
> For the gethostname, the max size is documented.
>
> 3) Is the GetComputerNameEx semantics right?
You are right. In summary:
- GetComputerNameEx(ComputerNameDnsHostname,...) returns the right hostname,
but it hard to use portably:
- It requires defining _WIN32_WINNT to at least 0x0500.
- With mingw, it also requires
"#define GetComputerNameEx GetComputerNameExA".
- With older versions of mingw, none of the declarations are present at
all, not even of the enum value ComputerNameDnsHostname.
- GetComputerName() does not return the right kind of hostname.
- gethostname() requires linking with -lws2_32.
I'm now convinced that linking with -lws2_32 is the least evil.
I have applied your patch from 2009-03-31.
Also, I'm fixing the handling of len > INT_MAX.
2009-08-02 Bruno Haible <br...@clisp.org>
* lib/gethostname.c (gethostname): Fix handling of large len argument.
Add comments.
--- lib/gethostname.c.orig 2009-08-02 12:02:00.000000000 +0200
+++ lib/gethostname.c 2009-08-02 11:59:12.000000000 +0200
@@ -21,6 +21,7 @@
#include <config.h>
#if !((defined _WIN32 || defined __WIN32__) && !defined __CYGWIN__)
+/* Unix API. */
/* Specification. */
#include <unistd.h>
@@ -59,6 +60,17 @@
}
#else
+/* Native Windows API. Which primitive to choose?
+ - gethostname() requires linking with -lws2_32.
+ - GetComputerName() does not return the right kind of hostname.
+ - GetComputerNameEx(ComputerNameDnsHostname,...) returns the right hostname,
+ but it hard to use portably:
+ - It requires defining _WIN32_WINNT to at least 0x0500.
+ - With mingw, it also requires
+ "#define GetComputerNameEx GetComputerNameExA".
+ - With older versions of mingw, none of the declarations are present at
+ all, not even of the enum value ComputerNameDnsHostname.
+ So we use gethostname(). Linking with -lws2_32 is the least evil. */
#define WIN32_LEAN_AND_MEAN
/* Get winsock2.h. */
@@ -70,9 +82,13 @@
#undef gethostname
int
-rpl_gethostname (char *name, size_t namelen)
+rpl_gethostname (char *name, size_t len)
{
- int r = gethostname (name, (int) namelen);
+ int r;
+
+ if (len > INT_MAX)
+ len = INT_MAX;
+ r = gethostname (name, (int) len);
if (r < 0)
set_winsock_errno ();
