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authorDenis Vlasenko2008-05-24 20:47:18 +0000
committerDenis Vlasenko2008-05-24 20:47:18 +0000
commit8e2c9e1518d42320ebd4b3ff09220d79a199e8ff (patch)
treeee565d0dbcbca18b33720aabc334d55ee39151da /miscutils/inotifyd.c
parente94a87134d2c78d3a1df39605d1f30d928a592a5 (diff)
downloadbusybox-8e2c9e1518d42320ebd4b3ff09220d79a199e8ff.zip
busybox-8e2c9e1518d42320ebd4b3ff09220d79a199e8ff.tar.gz
inotify: new applet by Vladimir Dronnikov <dronnikov AT gmail.com>
function old new delta inotifyd_main - 453 +453 packed_usage 24246 24450 +204 inotify_add_watch - 47 +47 inotify_init - 29 +29 mask_names - 13 +13 signal_handler 130 140 +10 applet_names 1859 1868 +9 applet_main 1132 1136 +4 applet_nameofs 566 568 +2 signalled 1 2 +1
Diffstat (limited to 'miscutils/inotifyd.c')
-rw-r--r--miscutils/inotifyd.c152
1 files changed, 152 insertions, 0 deletions
diff --git a/miscutils/inotifyd.c b/miscutils/inotifyd.c
new file mode 100644
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+++ b/miscutils/inotifyd.c
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+/* vi: set sw=4 ts=4: */
+/*
+ * simple inotify daemon
+ * reports filesystem changes via userspace agent
+ *
+ * Copyright (C) 2008 by Vladimir Dronnikov <dronnikov@gmail.com>
+ *
+ * Licensed under GPLv2, see file LICENSE in this tarball for details.
+ */
+
+/*
+ * Use as follows:
+ * # inotifyd /user/space/agent dir/or/file/being/watched[:mask] ...
+ *
+ * When a filesystem event matching the specified mask is occured on specified file (or directory)
+ * a userspace agent is spawned and given the following parameters:
+ * $1. actual event(s)
+ * $2. file (or directory) name
+ * $3. name of subfile (if any), in case of watching a directory
+ *
+ * E.g. inotifyd ./dev-watcher /dev:n
+ *
+ * ./dev-watcher can be, say:
+ * #!/bin/sh
+ * echo "We have new device in here! Hello, $3!"
+ *
+ * See below for mask names explanation.
+ */
+
+#include "libbb.h"
+#include <linux/inotify.h>
+
+static volatile smallint signalled;
+
+static void signal_handler(int signo)
+{
+ signalled = signo;
+}
+
+static const char mask_names[] ALIGN1 =
+ "a" // 0x00000001 File was accessed
+ "c" // 0x00000002 File was modified
+ "e" // 0x00000004 Metadata changed
+ "w" // 0x00000008 Writtable file was closed
+ "0" // 0x00000010 Unwrittable file closed
+ "r" // 0x00000020 File was opened
+ "m" // 0x00000040 File was moved from X
+ "y" // 0x00000080 File was moved to Y
+ "n" // 0x00000100 Subfile was created
+ "d" // 0x00000200 Subfile was deleted
+ "D" // 0x00000400 Self was deleted
+ "M" // 0x00000800 Self was moved
+;
+
+extern int inotify_init(void);
+extern int inotify_add_watch(int fd, const char *path, uint32_t mask);
+
+int inotifyd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int inotifyd_main(int argc ATTRIBUTE_UNUSED, char **argv)
+{
+ unsigned mask = IN_ALL_EVENTS; // assume we want all events
+ struct pollfd pfd;
+ char **watched = ++argv; // watched name list
+ const char *args[] = { *argv, NULL, NULL, NULL, NULL };
+
+ // sanity check: agent and at least one watch must be given
+ if (!argv[1])
+ bb_show_usage();
+
+ // open inotify
+ pfd.fd = inotify_init();
+ if (pfd.fd < 0)
+ bb_perror_msg_and_die("no kernel support");
+
+ // setup watched
+ while (*++argv) {
+ char *path = *argv;
+ char *masks = strchr(path, ':');
+ int wd; // watch descriptor
+ // if mask is specified ->
+ if (masks) {
+ *masks = '\0'; // split path and mask
+ // convert mask names to mask bitset
+ mask = 0;
+ while (*++masks) {
+ int i = strchr(mask_names, *masks) - mask_names;
+ if (i >= 0) {
+ mask |= (1 << i);
+ }
+ }
+ }
+ // add watch
+ wd = inotify_add_watch(pfd.fd, path, mask);
+ if (wd < 0) {
+ bb_perror_msg_and_die("add watch (%s) failed", path);
+// } else {
+// bb_error_msg("added %d [%s]:%4X", wd, path, mask);
+ }
+ }
+
+ // setup signals
+ bb_signals(0
+ + (1 << SIGHUP)
+ + (1 << SIGINT)
+ + (1 << SIGTERM)
+ + (1 << SIGPIPE)
+ , signal_handler);
+
+ // do watch
+
+// pfd.fd = fd;
+ pfd.events = POLLIN;
+
+ while (!signalled && poll(&pfd, 1, -1) > 0) {
+ ssize_t len;
+ void *buf;
+ struct inotify_event *ie;
+
+ // read out all pending events
+ xioctl(pfd.fd, FIONREAD, &len);
+#define eventbuf bb_common_bufsiz1
+ ie = buf = (len <= sizeof(eventbuf)) ? eventbuf : xmalloc(len);
+ len = full_read(pfd.fd, buf, len);
+ // process events. N.B. events may vary in length
+ while (len > 0) {
+ int i;
+ char events[12];
+ char *s = events;
+ unsigned m = ie->mask;
+
+ for (i = 0; i < 12; ++i, m >>= 1) {
+ if (m & 1) {
+ *s++ = mask_names[i];
+ }
+ }
+ *s = '\0';
+// bb_error_msg("exec %s %08X\t%s\t%s\t%s", agent, ie->mask, events, watched[ie->wd], ie->len ? ie->name : "");
+ args[1] = events;
+ args[2] = watched[ie->wd];
+ args[3] = ie->len ? ie->name : NULL;
+ xspawn((char **)args);
+ // next event
+ i = sizeof(struct inotify_event) + ie->len;
+ len -= i;
+ ie = (void*)((char*)ie + i);
+ }
+ if (eventbuf != buf)
+ free(buf);
+ }
+
+ return EXIT_SUCCESS;
+}