From 6958429d84cff06fefdc898d837a71c239f1e214 Mon Sep 17 00:00:00 2001 From: Ashwini Sharma Date: Fri, 23 May 2014 08:58:08 -0500 Subject: [PATCH] inotifyd - watch for filesystem events. --- toys/pending/inotifyd.c | 176 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 176 insertions(+) create mode 100644 toys/pending/inotifyd.c diff --git a/toys/pending/inotifyd.c b/toys/pending/inotifyd.c new file mode 100644 index 00000000..98de2546 --- /dev/null +++ b/toys/pending/inotifyd.c @@ -0,0 +1,176 @@ +/* inotifyd.c - inotify daemon. + * + * Copyright 2013 Ashwini Kumar + * Copyright 2013 Kyungwan Han + * + * No Standard. + +USE_INOTIFYD(NEWTOY(inotifyd, "<2", TOYFLAG_USR|TOYFLAG_BIN)) + +config INOTIFYD + bool "inotifyd" + default n + help + usage: inotifyd PROG FILE[:mask] ... + + Run PROG on filesystem changes. + When a filesystem event matching MASK occurs on FILEn, + PROG ACTUAL_EVENTS FILEn [SUBFILE] is run. + If PROG is -, events are sent to stdout. + + Events: + a File is accessed + c File is modified + e Metadata changed + w Writable file is closed + 0 Unwritable file is closed + r File is opened + D File is deleted + M File is moved + u Backing fs is unmounted + o Event queue overflowed + x File can't be watched anymore + If watching a directory: + m Subfile is moved into dir + y Subfile is moved out of dir + n Subfile is created + d Subfile is deleted + + inotifyd waits for PROG to exit. + When x event happens for all FILEs, inotifyd exits. +*/ +#define FOR_inotifyd +#include "toys.h" +#include + +GLOBALS( + int gotsignal; +) + +static void sig_handler(int sig) +{ + TT.gotsignal = sig; +} + +static int exec_wait(char **args) +{ + int status = 0; + pid_t pid = fork(); + + if (!pid) xexec(args); + else if (pid > 0) waitpid(pid, &status, 0); + else perror_exit("fork"); + return WEXITSTATUS(status); +} + +void inotifyd_main(void) +{ + struct pollfd fds; + char *prog_args[5], **files, **restore; + struct mask_nameval { + char name; + unsigned long val; + } mask_nv[] = { + { 'a', IN_ACCESS }, + { 'c', IN_MODIFY }, + { 'e', IN_ATTRIB }, + { 'w', IN_CLOSE_WRITE }, + { '0', IN_CLOSE_NOWRITE }, + { 'r', IN_OPEN }, + { 'm', IN_MOVED_FROM }, + { 'y', IN_MOVED_TO }, + { 'n', IN_CREATE }, + { 'd', IN_DELETE }, + { 'D', IN_DELETE_SELF }, + { 'M', IN_MOVE_SELF }, + { 'u', IN_UNMOUNT }, + { 'o', IN_Q_OVERFLOW }, + { 'x', IN_IGNORED } + }; + int mask, masks_len = ARRAY_LEN(mask_nv); + + prog_args[0] = toys.optargs[0]; + prog_args[4] = NULL; + toys.optc--; // 1st one is program, rest are files to be watched + //wd ZERO is not used, hence toys.optargs is assigned to files. + restore = files = toys.optargs; + if ((fds.fd = inotify_init()) == -1) perror_exit("initialization failed"); + + while (*++toys.optargs) { + char *path = *toys.optargs; + char *masks = strchr(path, ':'); + + mask = 0x0fff; //assuming all non-kernel events to be notified. + if (masks) { + *masks++ = '\0'; + mask = 0; + while (*masks) { + int i = 0; + + for (i = 0; i < masks_len; i++) { + if (*masks == mask_nv[i].name) { + mask |= mask_nv[i].val; + break; + } + } + if (i == masks_len) error_exit("wrong mask '%c'", *masks); + masks++; + } + } + if (inotify_add_watch(fds.fd, path, mask) < 0) + perror_exit("add watch '%s' failed", path); + } + toys.optargs = restore; + sigatexit(sig_handler); + fds.events = POLLIN; + + while (1) { + int ret = 0, queue_len; + void *buf = NULL; + struct inotify_event *event; + +retry: + if (TT.gotsignal) break; + ret = poll(&fds, 1, -1); + if (ret < 0 && errno == EINTR) goto retry; + if (ret <= 0) break; + xioctl(fds.fd, FIONREAD, &queue_len); + event = buf = xmalloc(queue_len); + queue_len = readall(fds.fd, buf, queue_len); + while (queue_len > 0) { + uint32_t m = event->mask; + + if (m) { + char evts[masks_len+1], *s = evts; + int i; + + for (i = 0; i < masks_len; i++) + if (m & mask_nv[i].val) *s++ = mask_nv[i].name; + *s = '\0'; + + if (prog_args[0][0] == '-' && !prog_args[0][1]) { //stdout + printf(event->len ? "%s\t%s\t%s\n" : "%s\t%s\n", evts, + files[event->wd], event->name); + fflush(stdout); + } else { + prog_args[1] = evts; + prog_args[2] = files[event->wd]; + prog_args[3] = event->len ? event->name : NULL; + exec_wait(prog_args); //exec and wait... + } + if (event->mask & IN_IGNORED) { + if (--toys.optc <= 0) { + free(buf); + goto done; + } + inotify_rm_watch(fds.fd, event->wd); + } + } + queue_len -= sizeof(struct inotify_event) + event->len; + event = (void*)((char*)event + sizeof(struct inotify_event) + event->len); //next event + } + free(buf); + } +done: + toys.exitval = TT.gotsignal; +} -- 2.11.0