cleanup src/linux and src/misc trees, etc.

previously, it was pretty much random which one of these trees a given
function appeared in. they have now been organized into:

src/linux: non-POSIX linux syscalls (possibly shard with other nixen)
src/legacy: various obsolete/legacy functions, mostly wrappers
src/misc: still mostly uncategorized; some misc POSIX, some nonstd
src/crypt: crypt hash functions

further cleanup will be done later.

1 files changed, 15 insertions, 0 deletions

diff --git a/src/misc/initgroups.c b/src/misc/initgroups.c
new file mode 100644
index 00000000..545d1859
--- /dev/null
+++ b/src/misc/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 = NGROUPS_MAX;
+	if (getgrouplist(user, gid, groups, &count) < 0) return -1;
+	return setgroups(count, groups);
+}