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Diffstat (limited to 'share/examples/inotify/inotify.c')
| -rw-r--r-- | share/examples/inotify/inotify.c | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/share/examples/inotify/inotify.c b/share/examples/inotify/inotify.c new file mode 100644 index 000000000000..ea63ccd1f337 --- /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->len > 0 ? 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); +} |