1INOTIFY_ADD_WATCH(2) Linux Programmer's Manual INOTIFY_ADD_WATCH(2)
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6 inotify_add_watch - add a watch to an initialized inotify instance
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9 #include <sys/inotify.h>
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11 int inotify_add_watch(int fd, const char *pathname, uint32_t mask);
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14 inotify_add_watch() adds a new watch, or modifies an existing watch,
15 for the file whose location is specified in pathname; the caller must
16 have read permission for this file. The fd argument is a file descrip‐
17 tor referring to the inotify instance whose watch list is to be modi‐
18 fied. The events to be monitored for pathname are specified in the
19 mask bit-mask argument. See inotify(7) for a description of the bits
20 that can be set in mask.
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22 A successful call to inotify_add_watch() returns the unique watch
23 descriptor associated with pathname for this inotify instance. If
24 pathname was not previously being watched by this inotify instance,
25 then the watch descriptor is newly allocated. If pathname was already
26 being watched, then the descriptor for the existing watch is returned.
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28 The watch descriptor is returned by later read(2)s from the inotify
29 file descriptor. These reads fetch inotify_event structures (see ino‐
30 tify(7)) indicating file system events; the watch descriptor inside
31 this structure identifies the object for which the event occurred.
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34 On success, inotify_add_watch() returns a non-negative watch descrip‐
35 tor. On error -1 is returned and errno is set appropriately.
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38 EACCES Read access to the given file is not permitted.
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40 EBADF The given file descriptor is not valid.
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42 EFAULT pathname points outside of the process's accessible address
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45 EINVAL The given event mask contains no valid events; or fd is not an
46 inotify file descriptor.
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48 ENOMEM Insufficient kernel memory was available.
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50 ENOSPC The user limit on the total number of inotify watches was
51 reached or the kernel failed to allocate a needed resource.
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54 Inotify was merged into the 2.6.13 Linux kernel.
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57 This system call is Linux-specific.
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60 inotify_init(2), inotify_rm_watch(2), inotify(7)
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63 This page is part of release 3.22 of the Linux man-pages project. A
64 description of the project, and information about reporting bugs, can
65 be found at http://www.kernel.org/doc/man-pages/.
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69Linux 2006-02-07 INOTIFY_ADD_WATCH(2)