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 zero (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 close 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
CAVEATS
When using inotifywait, the filename that is outputted is not guaranteed to be up to date after a move because it is the inode that is being monitored. Additionally, none of the observed operations are guaranteed to have been performed on the filename inotifywait was instructed to monitor in cases when the file is known by several names in the filesystem.
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 is written and maintained by Rohan McGovern <rohan@mcgovern.id.au>. inotifywait is part of inotify-tools. The inotify-tools website is located at: http://inotify-tools.sourceforge.net/
SEE ALSO
inotifywatch(1), strftime(3), inotify(7)
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