From 8e2c9e1518d42320ebd4b3ff09220d79a199e8ff Mon Sep 17 00:00:00 2001 From: Denis Vlasenko Date: Sat, 24 May 2008 20:47:18 +0000 Subject: inotify: new applet by Vladimir Dronnikov 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 --- miscutils/inotifyd.c | 152 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 152 insertions(+) create mode 100644 miscutils/inotifyd.c (limited to 'miscutils/inotifyd.c') diff --git a/miscutils/inotifyd.c b/miscutils/inotifyd.c new file mode 100644 index 000000000..0d7ad2a9d --- /dev/null +++ b/miscutils/inotifyd.c @@ -0,0 +1,152 @@ +/* vi: set sw=4 ts=4: */ +/* + * simple inotify daemon + * reports filesystem changes via userspace agent + * + * Copyright (C) 2008 by Vladimir Dronnikov + * + * 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 + +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; +} -- cgit v1.2.3