Add tests/bin/intr

This utility, inspired by the old SunOS 4.x intr(8) utility, will be
used to start daemons with --detach and a timeout, like this:

    intr -t 5 kdc --detach || { echo failed to start kdc; exit 1 }

This will allow tests to stop having to sleep poll for "started" output
from the daemons they start, allowing them to run faster and to impose a
reasonable timeout on daemon startup.

The default timeout is 3 seconds.

tests/bin/Makefile.am

@@ -2,6 +2,14 @@ include $(top_srcdir)/Makefile.am.common
 
 noinst_SCRIPTS = setup-env
 
+noinst_PROGRAMS = intr
+
+nodist_intr_SOURCES = intr.c
+
+CHECK_LOCAL = no-check-local
+
+intr_LDADD = $(LIB_roken)
+
 do_subst = \
 	top_srcdir="$$(cd ${top_srcdir} && pwd)" ; \
 	top_builddir="$$(cd ${top_builddir} && pwd)" ; \

tests/bin/intr.c

@@ -0,0 +1,56 @@
+#include <config.h>
+
+#include <getarg.h>
+#include <roken.h>
+#include <time.h>
+
+static int help_flag;
+static int timeout = 3;
+
+static struct getargs args[] = {
+    { "help", 'h', arg_flag, &help_flag, NULL, NULL },
+    { "timeout", 't', arg_integer, &timeout, NULL, NULL }
+};
+
+static int nargs = sizeof(args) / sizeof(args[0]);
+
+static time_t
+handle_timeout(void *data)
+{
+    static int killed;
+
+    if (!killed++)
+        return -1;  /* kill it */
+    return -2;      /* stop waiting for it */
+}
+
+static void
+usage(int status)
+{
+    arg_printusage(args, nargs, NULL, "command");
+    exit(status);
+}
+
+
+int
+main(int argc, char **argv)
+{
+    int optidx = 0;
+
+    setprogname(argv[0]);
+
+    if (getarg(args, nargs, argc, argv, &optidx))
+        usage(1);
+
+    if (help_flag)
+        usage(0);
+
+    argc -= optidx;
+    argv += optidx;
+
+    if (argc == 0)
+        usage(1);
+
+    return simple_execvp_timed(argv[0], argv, handle_timeout, NULL,
+                               timeout);
+}