The branch main has been updated by markj:
URL:
https://cgit.FreeBSD.org/src/commit/?id=1d8664d6904149e0be5dbfa0ee35268de2a83f1e
commit 1d8664d6904149e0be5dbfa0ee35268de2a83f1e
Author: Mark Johnston <ma...@freebsd.org>
AuthorDate: 2025-07-03 20:00:55 +0000
Commit: Mark Johnston <ma...@freebsd.org>
CommitDate: 2025-07-04 14:42:34 +0000
examples: Add a demo program for inotify
MFC after: 3 months
Sponsored by: Klara, Inc.
---
etc/mtree/BSD.usr.dist | 2 +
share/examples/Makefile | 5 ++
share/examples/inotify/Makefile | 6 ++
share/examples/inotify/inotify.c | 172 +++++++++++++++++++++++++++++++++++++++
4 files changed, 185 insertions(+)
diff --git a/etc/mtree/BSD.usr.dist b/etc/mtree/BSD.usr.dist
index 97b555e50dc1..ffdd82ae9911 100644
--- a/etc/mtree/BSD.usr.dist
+++ b/etc/mtree/BSD.usr.dist
@@ -304,6 +304,8 @@
..
indent
..
+ inotify
+ ..
ipfilter
..
ipfw
diff --git a/share/examples/Makefile b/share/examples/Makefile
index 560fdae6de5b..f0c050a36306 100644
--- a/share/examples/Makefile
+++ b/share/examples/Makefile
@@ -15,6 +15,7 @@ LDIRS= BSD_daemon \
find_interface \
flua \
indent \
+ inotify \
ipfw \
jails \
kld \
@@ -97,6 +98,10 @@ SE_FLUA= libjail.lua
SE_DIRS+= indent
SE_INDENT= indent.pro
+SE_DIRS+= inotify
+SE_INOTIFY= inotify.c \
+ Makefile
+
.if ${MK_IPFILTER} != "no"
SUBDIR+= ipfilter
.endif
diff --git a/share/examples/inotify/Makefile b/share/examples/inotify/Makefile
new file mode 100644
index 000000000000..c54c629c58d7
--- /dev/null
+++ b/share/examples/inotify/Makefile
@@ -0,0 +1,6 @@
+PROG= inotify
+MAN=
+
+LIBADD= xo
+
+.include <bsd.prog.mk>
diff --git a/share/examples/inotify/inotify.c b/share/examples/inotify/inotify.c
new file mode 100644
index 000000000000..b8e300bc992c
--- /dev/null
+++ b/share/examples/inotify/inotify.c
@@ -0,0 +1,172 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2025 Klara, Inc.
+ */
+
+/*
+ * A simple program to demonstrate inotify. Given one or more paths, it
watches
+ * all events on those paths and prints them to standard output.
+ */
+
+#include <sys/types.h>
+#include <sys/event.h>
+#include <sys/inotify.h>
+
+#include <assert.h>
+#include <err.h>
+#include <limits.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include <libxo/xo.h>
+
+static void
+usage(void)
+{
+ xo_errx(1, "usage: inotify <path1> [<path2> ...]");
+}
+
+static const char *
+ev2str(uint32_t event)
+{
+ switch (event & IN_ALL_EVENTS) {
+ case IN_ACCESS:
+ return ("IN_ACCESS");
+ case IN_ATTRIB:
+ return ("IN_ATTRIB");
+ case IN_CLOSE_WRITE:
+ return ("IN_CLOSE_WRITE");
+ case IN_CLOSE_NOWRITE:
+ return ("IN_CLOSE_NOWRITE");
+ case IN_CREATE:
+ return ("IN_CREATE");
+ case IN_DELETE:
+ return ("IN_DELETE");
+ case IN_DELETE_SELF:
+ return ("IN_DELETE_SELF");
+ case IN_MODIFY:
+ return ("IN_MODIFY");
+ case IN_MOVE_SELF:
+ return ("IN_MOVE_SELF");
+ case IN_MOVED_FROM:
+ return ("IN_MOVED_FROM");
+ case IN_MOVED_TO:
+ return ("IN_MOVED_TO");
+ case IN_OPEN:
+ return ("IN_OPEN");
+ default:
+ switch (event) {
+ case IN_IGNORED:
+ return ("IN_IGNORED");
+ case IN_Q_OVERFLOW:
+ return ("IN_Q_OVERFLOW");
+ case IN_UNMOUNT:
+ return ("IN_UNMOUNT");
+ }
+ warnx("unknown event %#x", event);
+ assert(0);
+ }
+}
+
+static void
+set_handler(int kq, int sig)
+{
+ struct kevent kev;
+
+ (void)signal(sig, SIG_IGN);
+ EV_SET(&kev, sig, EVFILT_SIGNAL, EV_ADD, 0, 0, NULL);
+ if (kevent(kq, &kev, 1, NULL, 0, NULL) < 0)
+ xo_err(1, "kevent");
+}
+
+int
+main(int argc, char **argv)
+{
+ struct inotify_event *iev, *iev1;
+ struct kevent kev;
+ size_t ievsz;
+ int ifd, kq;
+
+ argc = xo_parse_args(argc, argv);
+ if (argc < 2)
+ usage();
+ argc--;
+ argv++;
+
+ ifd = inotify_init1(IN_NONBLOCK);
+ if (ifd < 0)
+ xo_err(1, "inotify");
+ for (int i = 0; i < argc; i++) {
+ int wd;
+
+ wd = inotify_add_watch(ifd, argv[i], IN_ALL_EVENTS);
+ if (wd < 0)
+ xo_err(1, "inotify_add_watch(%s)", argv[i]);
+ }
+
+ xo_set_version("1");
+ xo_open_list("events");
+
+ kq = kqueue();
+ if (kq < 0)
+ xo_err(1, "kqueue");
+
+ /*
+ * Handle signals in the event loop so that we can close the xo list.
+ */
+ set_handler(kq, SIGINT);
+ set_handler(kq, SIGTERM);
+ set_handler(kq, SIGHUP);
+ set_handler(kq, SIGQUIT);
+
+ /*
+ * Monitor the inotify descriptor for events.
+ */
+ EV_SET(&kev, ifd, EVFILT_READ, EV_ADD, 0, 0, NULL);
+ if (kevent(kq, &kev, 1, NULL, 0, NULL) < 0)
+ xo_err(1, "kevent");
+
+ ievsz = sizeof(*iev) + NAME_MAX + 1;
+ iev = malloc(ievsz);
+ if (iev == NULL)
+ err(1, "malloc");
+
+ for (;;) {
+ ssize_t n;
+ const char *ev;
+
+ if (kevent(kq, NULL, 0, &kev, 1, NULL) < 0)
+ xo_err(1, "kevent");
+ if (kev.filter == EVFILT_SIGNAL)
+ break;
+
+ n = read(ifd, iev, ievsz);
+ if (n < 0)
+ xo_err(1, "read");
+ assert(n >= (ssize_t)sizeof(*iev));
+
+ for (iev1 = iev; n > 0;) {
+ assert(n >= (ssize_t)sizeof(*iev1));
+
+ ev = ev2str(iev1->mask);
+ xo_open_instance("event");
+ xo_emit("{:wd/%3d} {:event/%16s} {:name/%s}\n",
+ iev1->wd, ev, iev1->name);
+ xo_close_instance("event");
+
+ n -= sizeof(*iev1) + iev1->len;
+ iev1 = (struct inotify_event *)(void *)
+ ((char *)iev1 + sizeof(*iev1) + iev1->len);
+ }
+ (void)xo_flush();
+ }
+
+ xo_close_list("events");
+
+ if (xo_finish() < 0)
+ xo_err(1, "stdout");
+ exit(0);
+}
