当文件被删除并再次创建时，inotify 停止监视文件
我在使用inotify时遇到一些问题。 我使用 inotify 来监视文件的更改。这是我的代码：
int fd = inotify_init();
int wd = inotify_add_watch(fd, "/root/temp", IN_ALL_EVENTS);
int bufSize = 1000;
char *buf = new char[bufSize];
memset(buf, 0, sizeof(buf));
int nBytes = read(fd, buf, bufSize - 1);
cout << nBytes << " bytes read" << endl;
inotify_event *eventPtr = (inotify_event *)buf;
int offset = 0;
while (offset < nBytes)
{
cout << eventPtr->mask << endl;
offset += sizeof(inotify_event) + eventPtr->len;
eventPtr = (inotify_event *)(buf + offset);
}
delete []buf;
如果我删除“/root/temp”并重新创建这样的文件，inotify 不会监控对此文件的任何更改，有人知道这是怎么回事吗？谢谢。
程
I encounter some problem when using inotify.
I use inotify to monitor changes on files. Here is my code:
int fd = inotify_init();
int wd = inotify_add_watch(fd, "/root/temp", IN_ALL_EVENTS);
int bufSize = 1000;
char *buf = new char[bufSize];
memset(buf, 0, sizeof(buf));
int nBytes = read(fd, buf, bufSize - 1);
cout << nBytes << " bytes read" << endl;
inotify_event *eventPtr = (inotify_event *)buf;
int offset = 0;
while (offset < nBytes)
{
cout << eventPtr->mask << endl;
offset += sizeof(inotify_event) + eventPtr->len;
eventPtr = (inotify_event *)(buf + offset);
}
delete []buf;
If I delete "/root/temp" and re-create such a file, any changes to this file is not monitored by inotify, anyone how is this? Thanks.
cheng
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这是因为
inotify监视底层 inode ，而不是文件名。当您删除该文件时，您当前正在监视的 inode 将变得无效，因此您必须调用inotify_rm_watch。如果要监视具有相同名称但 inode 不同的新文件，则必须通过监视其父文件夹来检测该文件的创建时间。That's because
inotifymonitors the underlying inode, not the filename. When you delete that file, the inode you're currently watching becomes invalid, therefore, you must invokeinotify_rm_watch. If you want to monitor a new file with the same name, but a different inode, you must detect when it's created by monitoring its parent folder.另外两个答案是正确的。另一个有用的点是 inotify 会告诉你手表何时失效。
将不为零。
IN_IGNORED在以下情况下设置：“显式删除监视 (inotify_rm_watch(2)) 或自动删除（删除文件或卸载文件系统）。”
因此，如上所述，设置后，您可以重新观看文件（和/或目录，如果文件尚未重新创建）。
The other two answers are correct. Another useful point is that inotify tells you when the watch is invalidated.
will be non-zero.
IN_IGNOREDis set when:"Watch was removed explicitly (inotify_rm_watch(2)) or automatically (file was deleted, or file system was unmounted)."
So, as noted, when this is set, you can rewatch the file (and/or the directory if the file has not yet been re-created).
每当您使用 API 时，请阅读文档。
inotify 使用唯一的文件标识符 inode，而不是文件名来工作。事实上，整个 Linux 内核都与 inode 一起工作。文件名只是查找 inode 的一种方式。
要获得您想要的内容，您需要监视 /root 目录。添加文件时它将报告创建事件。如果该文件名为“temp”，那么您可以在该文件上添加监视。
Whenever you use an API, READ THE DOCUMENTATION.
inotify works using the unique file identifer inode, not a filename. The entire Linux kernel works with inodes in fact. Filenames are only a means to look up inodes.
To get what you want you need to monitor the /root directory. It will report a creation event when a file is added. If that file is named "temp" then you can add a watch on that file.