inotifywait

inotifywait(1)              General Commands Manual             inotifywait(1)



NAME
       inotifywait - wait for changes to files using inotify


SYNOPSIS
       inotifywait [-hcmrq] [-e <event> ] [-t <seconds> ] [--format <fmt> ]
       [--timefmt <fmt> ] <file> [ ... ]


DESCRIPTION
       inotifywait efficiently waits for changes to files using Linux's
       inotify(7) interface.  It is suitable for waiting for changes to files
       from shell scripts.  It can either exit once an event occurs, or
       continually execute and output events as they occur.


OUTPUT
       inotifywait will output diagnostic information on standard error and
       event information on standard output.  The event output can be
       configured, but by default it consists of lines of the following form:

       watched_filename EVENT_NAMES event_filename


       watched_filename
              is the name of the file on which the event occurred.  If the
              file is a directory, a trailing slash is output.

       EVENT_NAMES
              are the names of the inotify events which occurred, separated by
              commas.

       event_filename
              is output only when the event occurred on a directory, and in
              this case the name of the file within the directory which caused
              this event is output.

              By default, any special characters in filenames are not escaped
              in any way.  This can make the output of inotifywait difficult
              to parse in awk scripts or similar.  The --csv and --format
              options will be helpful in this case.


OPTIONS
       -h, --help
              Output some helpful usage information.

       @<file>
              When watching a directory tree recursively, exclude the
              specified file from being watched.  The file must be specified
              with a relative or absolute path according to whether a relative
              or absolute path is given for watched directories.  If a
              specific path is explicitly both included and excluded, it will
              always be watched.

              Note: If you need to watch a directory or file whose name starts
              with @, give the absolute path.

       --fromfile <file>
              Read filenames to watch or exclude from a file, one filename per
              line.  If filenames begin with @ they are excluded as described
              above.  If <file> is `-', filenames are read from standard
              input.  Use this option if you need to watch too many files to
              pass in as command line arguments.

       -m, --monitor
              Instead of exiting after receiving a single event, execute
              indefinitely.  The default behaviour is to exit after the first
              event occurs.

       -d, --daemon
              Same as --monitor, except run in the background logging events
              to a file that must be specified by --outfile. Implies --syslog.

       -o, --outfile <file>
              Output events to <file> rather than stdout.

       -s, --syslog
              Output errors to syslog(3) system log module rather than stderr.

       -r, --recursive
              Watch all subdirectories of any directories passed as arguments.
              Watches will be set up recursively to an unlimited depth.
              Symbolic links are not traversed.  Newly created subdirectories
              will also be watched.

              Warning: If you use this option while watching the root
              directory of a large tree, it may take quite a while until all
              inotify watches are established, and events will not be received
              in this time.  Also, since one inotify watch will be established
              per subdirectory, it is possible that the maximum amount of
              inotify watches per user will be reached.  The default maximum
              is 8192; it can be increased by writing to
              /proc/sys/fs/inotify/max_user_watches.


       -q, --quiet
              If specified once, the program will be less verbose.
              Specifically, it will not state when it has completed
              establishing all inotify watches.

              If specified twice, the program will output nothing at all,
              except in the case of fatal errors.


       --exclude <pattern>
              Do not process any events whose filename matches the specified
              POSIX extended regular expression, case sensitive.


       --excludei <pattern>
              Do not process any events whose filename matches the specified
              POSIX extended regular expression, case insensitive.


       -t <seconds>, --timeout <seconds>
              Exit if an appropriate event has not occurred within <seconds>
              seconds. If <seconds> is a negative value (the default), wait
              indefinitely for an event.


       -e <event>, --event <event>
              Listen for specific event(s) only.  The events which can be
              listened for are listed in the EVENTS section.  This option can
              be specified more than once.  If omitted, all events are
              listened for.


       -c, --csv
              Output in CSV (comma-separated values) format.  This is useful
              when filenames may contain spaces, since in this case it is not
              safe to simply split the output at each space character.


       --timefmt <fmt>
              Set a time format string as accepted by strftime(3) for use with
              the `%T' conversion in the --format option.


       --format <fmt>
              Output in a user-specified format, using printf-like syntax.
              The event strings output are limited to around 4000 characters
              and will be truncated to this length.  The following conversions
              are supported:


       %w     This will be replaced with the name of the Watched file on which
              an event occurred.


       %f     When an event occurs within a directory, this will be replaced
              with the name of the File which caused the event to occur.
              Otherwise, this will be replaced with an empty string.


       %e     Replaced with the Event(s) which occurred, comma-separated.


       %Xe    Replaced with the Event(s) which occurred, separated by
              whichever character is in the place of `X'.


       %T     Replaced with the current Time in the format specified by the
              --timefmt option, which should be a format string suitable for
              passing to strftime(3).




EXIT STATUS
       0      The program executed successfully, and an event occurred which
              was being listened for.

       1      An error occurred in execution of the program, or an event
              occurred which was not being listened for.  The latter generally
              occurs if something happens which forcibly removes the inotify
              watch, such as a watched file being deleted or the filesystem
              containing a watched file being unmounted.

       2      The -t option was used and an event did not occur in the
              specified interval of time.


EVENTS
       The following events are valid for use with the -e option:


       access A watched file or a file within a watched directory was read
              from.


       modify A watched file or a file within a watched directory was written
              to.


       attrib The metadata of a watched file or a file within a watched
              directory was modified.  This includes timestamps, file
              permissions, extended attributes etc.


       close_write
              A watched file or a file within a watched directory was closed,
              after being opened in writeable mode.  This does not necessarily
              imply the file was written to.


       close_nowrite
              A watched file or a file within a watched directory was closed,
              after being opened in read-only mode.


       close  A watched file or a file within a watched directory was closed,
              regardless of how it was opened.  Note that this is actually
              implemented simply by listening for both close_write and
              close_nowrite, hence all close events received will be output as
              one of these, not CLOSE.


       open   A watched file or a file within a watched directory was opened.


       moved_to
              A file or directory was moved into a watched directory.  This
              event occurs even if the file is simply moved from and to the
              same directory.


       moved_from
              A file or directory was moved from a watched directory.  This
              event occurs even if the file is simply moved from and to the
              same directory.


       move   A file or directory was moved from or to a watched directory.
              Note that this is actually implemented simply by listening for
              both moved_to and moved_from, hence all move events received
              will be output as one or both of these, not MOVE.


       move_self
              A watched file or directory was moved. After this event, the
              file or directory is no longer being watched.


       create A file or directory was created within a watched directory.


       delete A file or directory within a watched directory was deleted.


       delete_self
              A watched file or directory was deleted.  After this event the
              file or directory is no longer being watched.  Note that this
              event can occur even if it is not explicitly being listened for.


       unmount
              The filesystem on which a watched file or directory resides was
              unmounted.  After this event the file or directory is no longer
              being watched.  Note that this event can occur even if it is not
              explicitly being listened to.



EXAMPLES
   Example 1
       Running inotifywait at the command-line to wait for any file in the
       `test' directory to be accessed.  After running inotifywait, `cat
       test/foo' is run in a separate console.

       % inotifywait test
       Setting up watches.
       Watches established.
       test/ ACCESS foo


   Example 2
       A short shell script to efficiently wait for httpd-related log messages
       and do something appropriate.

       #!/bin/sh
       while ! inotifywait -e modify /var/log/messages; do
         if tail -n1 /var/log/messages | grep httpd; then
           kdialog --msgbox "Apache needs love!"
         fi
       done


   Example 3
       A custom output format is used to watch `~/test'.  Meanwhile, someone
       runs `touch ~/test/badfile; touch ~/test/goodfile; rm ~/test/badfile'
       in another console.

       % inotifywait -m -r --format '%:e %f' ~/test
       Setting up watches.  Beware: since -r was given, this may take a while!
       Watches established.
       CREATE badfile
       OPEN badfile
       ATTRIB badfile
       CLOSE_WRITE:CLOSE badfile
       CREATE goodfile
       OPEN goodfile
       ATTRIB goodfile
       CLOSE_WRITE:CLOSE goodfile
       DELETE badfile



BUGS
       There are race conditions in the recursive directory watching code
       which can cause events to be missed if they occur in a directory
       immediately after that directory is created.  This is probably not
       fixable.

       It is assumed the inotify event queue will never overflow.


AUTHORS
       inotifywait was started by Rohan McGovern, and is currently maintained
       by Eric Curtin and Radu Voicilas.  https://www.openhub.net/p/inotify-
       tools/contributors/summary gives you a more complete list of
       contributors.

       inotifywait is part of inotify-tools.  The inotify-tools website is
       located at: https://github.com/inotify-tools/inotify-tools/wiki


SEE ALSO
       inotifywatch(1), strftime(3), inotify(7)



inotifywait 3.20.2.1              2020-02-02                    inotifywait(1)