Add grent(3).

libc/Makefile

@@ -200,6 +200,7 @@ getppid.o \
 gettermmode.o \
 gettimeofday.o \
 getuid.o \
+grent.o \
 init.o \
 ioctl.o \
 ioleast.o \

libc/grent.cpp

@@ -0,0 +1,67 @@
+/*******************************************************************************
+
+    Copyright(C) Jonas 'Sortie' Termansen 2013.
+
+    This file is part of the Sortix C Library.
+
+    The Sortix C Library is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or (at your
+    option) any later version.
+
+    The Sortix C Library is distributed in the hope that it will be useful, but
+    WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+    or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
+    License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with the Sortix C Library. If not, see <http://www.gnu.org/licenses/>.
+
+    grent.cpp
+    Group database.
+
+*******************************************************************************/
+
+#include <sys/types.h>
+
+#include <grp.h>
+#include <stdlib.h>
+#include <string.h>
+
+const gid_t ROOT_GID = 0;
+const char* const ROOT_NAME = "root";
+
+static struct group global_group;
+
+static struct group* fill_group(struct group* gr)
+{
+	const char* env_groupname = getenv("GROUPNAME");
+	strcpy(gr->gr_name, env_groupname ? env_groupname : ROOT_NAME);
+	const char* env_groupid = getenv("GROUPID");
+	gr->gr_gid = env_groupid ? atoi(env_groupid) : ROOT_GID;
+	return gr;
+}
+
+static gid_t lookup_groupname(const char* name)
+{
+	const char* env_groupname = getenv("GROUPNAME");
+	const char* my_groupname = env_groupname ? env_groupname : ROOT_NAME;
+	if ( !strcmp(my_groupname, name) )
+	{
+		const char* env_groupid = getenv("GROUPID");
+		if ( env_groupid )
+			return atoi(env_groupid);
+	}
+	return 1;
+}
+
+extern "C" struct group* getgrgid(gid_t gid)
+{
+	(void) gid;
+	return fill_group(&global_group);
+}
+
+extern "C" struct group* getgrnam(const char* name)
+{
+	return getgrgid(lookup_groupname(name));
+}

libc/include/grp.h

@@ -0,0 +1,50 @@
+/*******************************************************************************
+
+    Copyright(C) Jonas 'Sortie' Termansen 2013.
+
+    This file is part of the Sortix C Library.
+
+    The Sortix C Library is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or (at your
+    option) any later version.
+
+    The Sortix C Library is distributed in the hope that it will be useful, but
+    WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+    or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
+    License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with the Sortix C Library. If not, see <http://www.gnu.org/licenses/>.
+
+    grp.h
+    Group database.
+
+*******************************************************************************/
+
+#ifndef INCLUDE_GRP_H
+#define INCLUDE_GRP_H
+
+#include <features.h>
+
+__BEGIN_DECLS
+
+@include(gid_t.h)
+@include(uid_t.h)
+@include(size_t.h)
+
+#define _GROUP_BUFFER_SIZE 64
+
+struct group
+{
+	char gr_name[_GROUP_BUFFER_SIZE];
+	gid_t gr_gid;
+	char** gr_mem;
+};
+
+struct group* getgrgid(gid_t gid);
+struct group* getgrnam(const char* name);
+
+__END_DECLS
+
+#endif