initial check-in, version 0.5.0

src/linux/initgroups.c

@@ -0,0 +1,15 @@
+#include <sys/types.h>
+#include <unistd.h>
+#include <grp.h>
+#include <limits.h>
+
+int getgrouplist(const char *, gid_t, gid_t *, int *);
+int setgroups(size_t, const gid_t *);
+
+int initgroups(const char *user, gid_t gid)
+{
+	gid_t groups[NGROUPS_MAX];
+	int count;
+	if (getgrouplist(user, gid, groups, &count) < 0) return -1;
+	return setgroups(count, groups);
+}