[musl] [PATCH v2] extend gethostid beyond a stub

["Érico Rolim" <ericonr@disroot.org>]

From: Érico Rolim <erico.erc@gmail.com>

Implement part of the glibc behavior, where the 32-bit identifier stored
in /etc/hostid, if the file exists, is returned. If this file doesn't
contain at least 32 bits or can't be opened for some reason, return 0.
---

> The glibc implementation appears to read and write directly into an
> int32_t variable, without any endianness conversion. To be
> interoperable with /etc/hostid files created by glibc shouldn't musl
> skip the ntohl() and just return x ?

I have changed it to directly read the file into a variable. Given that
the return type is long, should I still use int32_t inside the function?

 src/misc/gethostid.c | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/src/misc/gethostid.c b/src/misc/gethostid.c
index 25bb35db..2877842f 100644
--- a/src/misc/gethostid.c
+++ b/src/misc/gethostid.c
@@ -1,6 +1,18 @@
 #include <unistd.h>
+#include <stdio.h>
 
 long gethostid()
 {
-	return 0;
+	FILE *f;
+	long rv = 0;
+
+	f = fopen("/etc/hostid", "reb");
+	if (f) {
+		if (fread(&rv, 4, 1, f) == 0) {
+			rv = 0;
+		}
+		fclose(f);
+	}
+
+	return rv;
 }
-- 
2.28.0