sysctlbyname allows acces to sysctl variables by name.

The manpage has been sent to linquistic decontamination and will arrive
when released from the quarantine

Reviewed by:	peter

2 files changed, 35 insertions, 2 deletions

diff --git a/lib/libc/gen/Makefile.inc b/lib/libc/gen/Makefile.inc
index 4f13707..e5f7a28 100644
--- a/lib/libc/gen/Makefile.inc
+++ b/lib/libc/gen/Makefile.inc
@@ -1,5 +1,5 @@
 #	@(#)Makefile.inc	8.6 (Berkeley) 5/4/95
-#	$Id: Makefile.inc,v 1.31 1997/04/13 15:12:14 davidn Exp $
+#	$Id: Makefile.inc,v 1.33 1997/05/03 03:49:54 jb Exp $
 
 # machine-independent gen sources
 .PATH: ${.CURDIR}/../libc/${MACHINE}/gen ${.CURDIR}/../libc/gen
@@ -17,7 +17,7 @@ SRCS+=	alarm.c assert.c clock.c closedir.c config.c confstr.c crypt.c \
 	scandir.c seekdir.c semconfig.c semctl.c semget.c semop.c \
 	setdomainname.c sethostname.c setjmperr.c setmode.c shmat.c \
 	shmctl.c shmdt.c shmget.c siginterrupt.c siglist.c signal.c \
-	sigsetops.c sleep.c sysconf.c sysctl.c syslog.c \
+	sigsetops.c sleep.c sysconf.c sysctl.c sysctlbyname.c syslog.c \
 	telldir.c termios.c time.c times.c timezone.c ttyname.c ttyslot.c \
 	ualarm.c uname.c unvis.c usleep.c utime.c valloc.c vis.c wait.c \
 	wait3.c waitpid.c
diff --git a/lib/libc/gen/sysctlbyname.c b/lib/libc/gen/sysctlbyname.c
new file mode 100644
index 0000000..a3133af
--- /dev/null
+++ b/lib/libc/gen/sysctlbyname.c
@@ -0,0 +1,33 @@
+/*
+ * ----------------------------------------------------------------------------
+ * "THE BEER-WARE LICENSE" (Revision 42):
+ * <phk@FreeBSD.org> wrote this file.  As long as you retain this notice you
+ * can do whatever you want with this stuff. If we meet some day, and you think
+ * this stuff is worth it, you can buy me a beer in return.   Poul-Henning Kamp
+ * ----------------------------------------------------------------------------
+ *
+ * $Id$
+ *
+ */
+#include <sys/types.h>
+#include <sys/sysctl.h>
+
+int
+sysctlbyname(char *name, void *oldp, size_t *oldlenp, void *newp, size_t newlen)
+{
+	int name2oid_oid[2];
+	int real_oid[CTL_MAXNAME+2];
+	int error, oidlen;
+
+	name2oid_oid[0] = 0;	/* This is magic & undocumented! */
+	name2oid_oid[1] = 3;
+
+	oidlen = sizeof(real_oid);
+	error = sysctl(name2oid_oid, 2, real_oid, &oidlen, name, strlen(name));
+	if (error < 0) 
+		return error;
+	oidlen /= sizeof (int);
+	error = sysctl(real_oid, oidlen, oldp, oldlenp, newp, newlen);
+	return (error);
+}
+