how to check if the file is changed using stat linux command

Question

I want to check if a file is changed or no using stat linux command.

linux@server:~/$ stat test.txt File: `test.txt' Size: 23
Blocks: 8 IO Block: 4096 regular file Device: 802h/2050d Inode: 4887765 Links: 1

Access: (0644/-rw-r--r--) Uid: ( 1000/ anis) Gid: ( 1000/
anis)

Access: 2014-07-07 16:34:42.476315578 +0200

Modify: 2014-07-08 12:54:15.756553868 +0200

Change: 2014-07-08 12:54:15.756553868 +0200

we can see the time of change. the purpose is to use this change time to check if the file is modified or no

linux@server:~/anis$ stat test.txt |grep Change
Change: 2014-07-08 12:54:15.756553868 +0200

linux@server:~/anis$ stat test.txt |grep Change

Change: 2014-07-08 15:14:03.107977776 +0200

so how made script running in infinite loop to check if time is changed ?

Maybe look at `inotify` rather than polling. – Mark Setchell Jul 08 '14 at 13:51 — Mark Setchell, Jul 08 '14 at 13:51
`man inotifywait` and `man inotifywatch` – William Pursell Jul 08 '14 at 13:51 — William Pursell, Jul 08 '14 at 13:51

score 2 · Answer 1 · answered Jul 08 '14 at 13:54

2

Don't use stat. To simply block until the file is modified, use inotifywait:

inotifywait -e modify test.txt

You may want to wait for a less restrictive set of changes:

inotifywait test.txt

will block until any event happens on the file. Also, consider the sanity of your users:

inotifywait -qq test.txt

answered Jul 08 '14 at 13:54

William Pursell

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inotifywait run on OpenWrt ? because inotifyd doesn't work on OpenWrt – Anis_Stack Jul 08 '14 at 14:23
The question is tagged 'linux'. If you need a solution for an embedded system, that should be specified in the question or the tags. – William Pursell Jul 08 '14 at 14:28
in fact in first time I installed inotify on OpenWrt but it doesn't work, so for this reason I look for solution with other tools. – Anis_Stack Jul 08 '14 at 14:36

score 0 · Answer 2 · answered Jul 08 '14 at 14:43

If you are using OpenWrt Buildroot, then you can select and install inotify-tools during the configuration (make menuconfig, or what ever configuration ui you are using).

After that you can use inotifywait just as William Pursell suggested.

The package inotify-tools was added by with this patch in 2011.

how to check if the file is changed using stat linux command

2 Answers2