last time file opened
This depends on exactly what you mean by "opened", but in general, yes. There are three timestamps normally recorded:
mtime
— updated when the file contents change. This is the "default" file time in most cases.ctime
— updated when the file or its metadata (owner, permissions) changeatime
— updated when the file is read
So, generally, what you want to see is the atime
of a file. You can get that with stat
or with ls
. You can use ls -lu
to do this, although I prefer to use ls -l --time=atime
(which should be supported in almost all modern Linux distributions) because I don't use it often, and when I do I can remember it better. And to sort by time, add the -t
flag to ls. So there you go.
There is a big caveat, though. Updating the atime every time a file is read causes a lot of usually-unnecessary IO, slowing everything down. So, most Linux distributions now default to the noatime
filesystem mount option, which basically kills atimes, or else relatime
, which only updates atimes once a limit has passed (normally once per day) or if the file was actually modified since the previous read. You can find if these options are active by running the mount
command.
Also, note that access times are by inode, not by filename, so if you have hardlinks, reading from one will update all names that refer to the same file.
And, be aware that c is not "creation"; creation isn't tracked by Unix/Linux filesystems, which seems strange but actually makes sense because the filesystem has no way of knowing if it is the original — maybe the file was created forty years ago and copied here. And, in fact, many file editors work by making copies over the original. If you need that information, it's best to use a version control system like git
.
ls -ltu
list all the files, showing and sorting by access time.
From man ls
:
-u with -lt: sort by, and show, access time with -l: show access
time and sort by name otherwise: sort by access time
The find
command is best for this. See the -ctime
, -mtime
, and -atime
options