Import pwcache module from OpenBSD

test/.gitignore

@@ -15,6 +15,7 @@ overlay
 proctitle-init
 proctitle
 progname
+pwcache
 setmode
 strl
 strmode

test/Makefile.am

@@ -43,6 +43,7 @@ check_PROGRAMS = \
 	nlist \
 	proctitle-init \
 	progname \
+	pwcache \
 	setmode \
 	strl \
 	strmode \

test/overlay.c

@@ -28,6 +28,9 @@
  * other headers through magic macros, to check that the overlay is working
  * properly. */
 #include <errno.h>
+#ifdef HAVE_PWD_H
+#include <pwd.h>
+#endif
 #ifdef HAVE_GRP_H
 #include <grp.h>
 #endif

test/pwcache.c

@@ -0,0 +1,49 @@
+/*
+ * Copyright © 2021 Guillem Jover <guillem@hadrons.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL
+ * THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+ * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+ * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <assert.h>
+#include <string.h>
+#include <pwd.h>
+#include <grp.h>
+
+int
+main(int argc, char **argv)
+{
+	uid_t uid;
+	gid_t gid;
+
+	assert(uid_from_user("root", &uid) == 0);
+	assert(uid == 0);
+
+	assert(strcmp(user_from_uid(0, 0), "root") == 0);
+
+	assert(gid_from_group("root", &gid) == 0);
+	assert(gid == 0);
+
+	assert(strcmp(group_from_gid(0, 0), "root") == 0);
+
+	return 0;
+}