+/* epoll_inotify_monitor.c
+ *
+ * Copyright (C) 2007 Simone Piccardi
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or (at
+ * your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+/*****************************************************************************
+ *
+ * File epoll_inotify_monitor.c:
+ *
+ * An example of the inotify and epoll interface: use inotify to watch the
+ * status of a directory or a file and epoll to wait for inotify events.
+ *
+ * Author: S. Piccardi Jul. 2007
+ *
+ *****************************************************************************/
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/inotify.h> /* Linux inotify interface */
+#include <sys/epoll.h> /* Linux epoll interface */
+#include <stdlib.h> /* C standard library */
+#include <unistd.h> /* Unix standard library */
+#include <errno.h> /* error definitions and routines */
+#include <stdio.h> /* standard I/O library */
+#include <string.h> /* string functions */
+#include <fcntl.h> /* fcntl function */
+#include <sys/ioctl.h> /* ioctl function */
+
+
+#include "macros.h"
+
+/* Help printing routine */
+void usage(void);
+void printevent(unsigned int mask);
+
+int main(int argc, char *argv[])
+{
+ int i, size, nread;
+ int fd, wd, epfd;
+ char buffer[1024 + sizeof(struct inotify_event)];
+ unsigned int mask=0;
+ struct inotify_event * event;
+ struct epoll_event epev;
+ /*
+ * Input section: decode command line parameters
+ * Use getopt function
+ */
+ opterr = 0; /* don't want writing to stderr */
+ while ((i = getopt(argc, argv, "hrwcda")) != -1) {
+ switch (i) {
+ /*
+ * Handling options
+ */
+ case 'h': /* help option */
+ printf("Wrong -h option use\n");
+ usage();
+ case 'r': /* read access */
+ mask |= IN_ACCESS;
+ break;
+ case 'w': /* write access */
+ mask |= IN_MODIFY;
+ break;
+ case 'c': /* creation */
+ mask |= IN_CREATE;
+ break;
+ case 'd': /* deletion */
+ mask |= IN_DELETE;
+ break;
+ case 'a': /* all events */
+ mask |= IN_ALL_EVENTS;
+ break;
+ case '?': /* unrecognized options */
+ printf("Unrecognized options -%c\n",optopt);
+ usage();
+ default: /* should not reached */
+ usage();
+ }
+ }
+ /* ***********************************************************
+ *
+ * Options processing completed
+ *
+ * Main code beginning
+ *
+ * ***********************************************************/
+ if ((argc - optind) != 1) { /* There must be one argument */
+ printf("Wrong number of arguments %d\n", argc - optind);
+ usage();
+ }
+ epfd = epoll_create(5); /* initialize epoll */
+ if (epfd < 0) {
+ perror("Failing on epoll_create");
+ exit(-1);
+ }
+ fd = inotify_init(); /* initialize inotify */
+ if (fd < 0) {
+ perror("Failing on inotify_init");
+ exit(-1);
+ }
+ if (fcntl(fd, F_SETFL, O_NONBLOCK)) { /* no blocking I/O on inotify */
+ perror("Cannot set noblocking I/O on inotify fd");
+ exit(-1);
+ }
+ wd = inotify_add_watch(fd, argv[optind], mask); /* add watch */
+ if (wd <= 0) {
+ printf("Failing to add watched file %s, mask %i; %s\n",
+ argv[optind], mask, strerror(errno));
+ exit(-1);
+ }
+ epev.data.fd = fd; /* add inotify fd to epoll */
+ epev.events = EPOLLIN;
+ if (epoll_ctl(epfd, EPOLL_CTL_ADD, fd, &epev)) {
+ perror("Failing on epoll_ctl");
+ exit(-1);
+ }
+ /*
+ * Main Loop: read events and print them
+ */
+ while (1) {
+ if (epoll_wait(epfd, &epev, 1, -1) < 0) {
+ perror("error on epoll_wait");
+ exit(-1);
+ }
+ if (epev.data.fd != fd)
+ printf("something wrong, epoll activity on %i instead of %i\n",
+ epev.data.fd, fd);
+
+ if (ioctl(fd, FIONREAD, &size)) {
+ perror("error on getting inotify event size");
+ exit(-1);
+ }
+ if (size > sizeof(buffer)) {
+ printf("Too many %i data to read, something wrong\n", size);
+ exit(-1);
+ }
+ i = 0;
+ while (i < size) {
+ nread = read(fd, buffer, size);
+ if (nread < 0) {
+ perror("error reading inotify data");
+ exit(1);
+ }
+ i += nread;
+ event = (struct inotify_event *) buffer;
+ if (wd != event->wd) {
+ printf("Getting different watch descriptor, %i and %i\n",
+ wd, event->wd);
+ } else {
+ printf("Observed event on %s\n", argv[optind-1+event->wd]);
+ if (event->name != NULL)
+ printf("On file %s\n", event->name);
+ printevent(event->mask);
+ }
+ }
+ }
+ return 0;
+}
+/*
+ * routine to print usage info and exit
+ */
+void usage(void) {
+ printf("Program inotify_monitor: monitor file changes \n");
+ printf("Usage:\n");
+ printf(" inotify_monitor [-h] -rwcd dirname/filename dir/file ... \n");
+ printf(" -h print this help\n");
+ printf(" -w watch write\n");
+ printf(" -r watch read\n");
+ printf(" -c watch create\n");
+ printf(" -d watch delete\n");
+ printf(" -a watch all\n");
+ exit(1);
+}
+
+void printevent(unsigned int mask) {
+ int i;
+ int val;
+ char * inotify_event[] = {
+ "IN_ACCESS",
+ "IN_MODIFY",
+ "IN_ATTRIB",
+ "IN_CLOSE_WRITE",
+ "IN_CLOSE_NOWRITE",
+ "IN_OPEN",
+ "IN_MOVED_FROM",
+ "IN_MOVED_TO",
+ "IN_CREATE",
+ "IN_DELETE",
+ "IN_DELETE_SELF",
+ "IN_MOVE_SELF",
+ "ERROR!!!",
+ "IN_UNMOUNT",
+ "IN_Q_OVERFLOW",
+ "IN_IGNORED"
+ };
+
+ val=1;
+ for (i=0; i<16; i++) {
+ if (mask & val)
+ printf("%s, ", inotify_event[i]);
+ val = val << 1;
+ }
+ printf("\n");
+}
projects / gapil.git / commitdiff