X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=miscutils%2Finotifyd.c;h=0060797edec5c1a4c003c043c792be8ee9e1cce9;hb=73af705628ddaedc4c6f7f78b9658d6c01310309;hp=0d7ad2a9d5c68147d1aca342b30e00b9256d0516;hpb=8e2c9e1518d42320ebd4b3ff09220d79a199e8ff;p=oweals%2Fbusybox.git diff --git a/miscutils/inotifyd.c b/miscutils/inotifyd.c index 0d7ad2a9d..0060797ed 100644 --- a/miscutils/inotifyd.c +++ b/miscutils/inotifyd.c @@ -5,14 +5,14 @@ * * Copyright (C) 2008 by Vladimir Dronnikov * - * Licensed under GPLv2, see file LICENSE in this tarball for details. + * Licensed under GPLv2, see file LICENSE in this source tree. */ /* * 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) + * When a filesystem event matching the specified mask is occurred on specified file (or directory) * a userspace agent is spawned and given the following parameters: * $1. actual event(s) * $2. file (or directory) name @@ -26,23 +26,55 @@ * * See below for mask names explanation. */ +//config:config INOTIFYD +//config: bool "inotifyd (3.5 kb)" +//config: default n # doesn't build on Knoppix 5 +//config: help +//config: Simple inotify daemon. Reports filesystem changes. Requires +//config: kernel >= 2.6.13 + +//applet:IF_INOTIFYD(APPLET(inotifyd, BB_DIR_SBIN, BB_SUID_DROP)) + +//kbuild:lib-$(CONFIG_INOTIFYD) += inotifyd.o + +//usage:#define inotifyd_trivial_usage +//usage: "PROG FILE1[:MASK]..." +//usage:#define inotifyd_full_usage "\n\n" +//usage: "Run PROG on filesystem changes." +//usage: "\nWhen a filesystem event matching MASK occurs on FILEn," +//usage: "\nPROG ACTUAL_EVENTS FILEn [SUBFILE] is run." +//usage: "\nIf PROG is -, events are sent to stdout." +//usage: "\nEvents:" +//usage: "\n a File is accessed" +//usage: "\n c File is modified" +//usage: "\n e Metadata changed" +//usage: "\n w Writable file is closed" +//usage: "\n 0 Unwritable file is closed" +//usage: "\n r File is opened" +//usage: "\n D File is deleted" +//usage: "\n M File is moved" +//usage: "\n u Backing fs is unmounted" +//usage: "\n o Event queue overflowed" +//usage: "\n x File can't be watched anymore" +//usage: "\nIf watching a directory:" +//usage: "\n y Subfile is moved into dir" +//usage: "\n m Subfile is moved out of dir" +//usage: "\n n Subfile is created" +//usage: "\n d Subfile is deleted" +//usage: "\n" +//usage: "\ninotifyd waits for PROG to exit." +//usage: "\nWhen x event happens for all FILEs, inotifyd exits." #include "libbb.h" -#include - -static volatile smallint signalled; - -static void signal_handler(int signo) -{ - signalled = signo; -} +#include "common_bufsiz.h" +#include 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 + "w" // 0x00000008 Writable file was closed + "0" // 0x00000010 Unwritable file closed "r" // 0x00000020 File was opened "m" // 0x00000040 File was moved from X "y" // 0x00000080 File was moved to Y @@ -50,95 +82,135 @@ static const char mask_names[] ALIGN1 = "d" // 0x00000200 Subfile was deleted "D" // 0x00000400 Self was deleted "M" // 0x00000800 Self was moved + "\0" // 0x00001000 (unused) + // Kernel events, always reported: + "u" // 0x00002000 Backing fs was unmounted + "o" // 0x00004000 Event queued overflowed + "x" // 0x00008000 File is no longer watched (usually deleted) ; - -extern int inotify_init(void); -extern int inotify_add_watch(int fd, const char *path, uint32_t mask); +enum { + MASK_BITS = sizeof(mask_names) - 1 +}; int inotifyd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; -int inotifyd_main(int argc ATTRIBUTE_UNUSED, char **argv) +int inotifyd_main(int argc, char **argv) { - unsigned mask = IN_ALL_EVENTS; // assume we want all events + int n; + unsigned mask; struct pollfd pfd; - char **watched = ++argv; // watched name list - const char *args[] = { *argv, NULL, NULL, NULL, NULL }; + char **watches; // names of files being watched + const char *args[5]; // sanity check: agent and at least one watch must be given - if (!argv[1]) + if (!argv[1] || !argv[2]) bb_show_usage(); + argv++; + // inotify_add_watch will number watched files + // starting from 1, thus watches[0] is unimportant, + // and 1st file name is watches[1]. + watches = argv; + args[0] = *argv; + args[4] = NULL; + argc -= 2; // number of files we watch + // open inotify pfd.fd = inotify_init(); if (pfd.fd < 0) bb_perror_msg_and_die("no kernel support"); - // setup watched + // setup watches while (*++argv) { char *path = *argv; char *masks = strchr(path, ':'); - int wd; // watch descriptor + + mask = 0x0fff; // assuming we want all non-kernel events // 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); - } + const char *found; + found = memchr(mask_names, *masks, MASK_BITS); + if (found) + mask |= (1 << (found - mask_names)); } } // add watch - wd = inotify_add_watch(pfd.fd, path, mask); - if (wd < 0) { + n = inotify_add_watch(pfd.fd, path, mask); + if (n < 0) bb_perror_msg_and_die("add watch (%s) failed", path); -// } else { -// bb_error_msg("added %d [%s]:%4X", wd, path, mask); - } + //bb_error_msg("added %d [%s]:%4X", n, path, mask); } // setup signals - bb_signals(0 - + (1 << SIGHUP) - + (1 << SIGINT) - + (1 << SIGTERM) - + (1 << SIGPIPE) - , signal_handler); + bb_signals(BB_FATAL_SIGS, record_signo); // do watch - -// pfd.fd = fd; pfd.events = POLLIN; - - while (!signalled && poll(&pfd, 1, -1) > 0) { - ssize_t len; + while (1) { + int len; void *buf; struct inotify_event *ie; + again: + if (bb_got_signal) + break; + n = poll(&pfd, 1, -1); + // Signal interrupted us? + if (n < 0 && errno == EINTR) + goto again; + // Under Linux, above if() is not necessary. + // Non-fatal signals, e.g. SIGCHLD, when set to SIG_DFL, + // are not interrupting poll(). + // Thus we can just break if n <= 0 (see below), + // because EINTR will happen only on SIGTERM et al. + // But this might be not true under other Unixes, + // and is generally way too subtle to depend on. + if (n <= 0) // strange error? + break; // read out all pending events - xioctl(pfd.fd, FIONREAD, &len); + // (NB: len must be int, not ssize_t or long!) #define eventbuf bb_common_bufsiz1 - ie = buf = (len <= sizeof(eventbuf)) ? eventbuf : xmalloc(len); + setup_common_bufsiz(); + xioctl(pfd.fd, FIONREAD, &len); + ie = buf = (len <= COMMON_BUFSIZE) ? 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]; + // cache relevant events mask + unsigned m = ie->mask & ((1 << MASK_BITS) - 1); + if (m) { + char events[MASK_BITS + 1]; + char *s = events; + for (i = 0; i < MASK_BITS; ++i, m >>= 1) { + if ((m & 1) && (mask_names[i] != '\0')) + *s++ = mask_names[i]; + } + *s = '\0'; + if (LONE_CHAR(args[0], '-')) { + /* "inotifyd - FILE": built-in echo */ + printf(ie->len ? "%s\t%s\t%s\n" : "%s\t%s\n", events, + watches[ie->wd], + ie->name); + fflush(stdout); + } else { +// bb_error_msg("exec %s %08X\t%s\t%s\t%s", args[0], +// ie->mask, events, watches[ie->wd], ie->len ? ie->name : ""); + args[1] = events; + args[2] = watches[ie->wd]; + args[3] = ie->len ? ie->name : NULL; + spawn_and_wait((char **)args); + } + // we are done if all files got final x event + if (ie->mask & 0x8000) { + if (--argc <= 0) + goto done; + inotify_rm_watch(pfd.fd, ie->wd); } } - *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; @@ -146,7 +218,7 @@ int inotifyd_main(int argc ATTRIBUTE_UNUSED, char **argv) } if (eventbuf != buf) free(buf); - } - - return EXIT_SUCCESS; + } // while (1) + done: + return bb_got_signal; }