CentOS - Sep 2005 - how to tell if a file is older than 30 days?

I am trying to find out how to tell if a given file is 30 days or older.
How is that type of thing done in shell scripts.

Thanks,

Jerry

-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<http://lists.centos.org/pipermail/centos/attachments/20050915/e412e896/attachment.html>

> I am trying to find out how to tell if a given file is 30 days or 
> older.
>  How is that type of thing done in shell scripts.
You want to get the modification time of the file most likely.  This 
can be done using the "stat" command.  This will return the "Time
of
last modification as seconds since Epoch" of the given file:

   stat --format="%Y" /path/to/file

Just compare this number to the current time (in seconds since Epoch) 
and you can determine the age of a file.

Alfred

From: Jerry Geis [mailto:geisj at pagestation.com]
> 
> I am trying to find out how to tell if a given file is 30 days or older.
> How is that type of thing done in shell scripts.
find directoryname -mtime +30 -print

Will list all files in a directory that have not been modified in the last
30 days.

Read the man page for 'find'.  It can find files based on almost
anything.

Bowie

[ We could _really_ use a "practices" list. ;-]

Jerry Geis <geisj at pagestation.com> wrote:
> I am trying to find out how to tell if a given file is 30
> days or older.
Do you mean accessed time (atime), changed attributes time
(ctime) or modification time (mtime)?  I'll assume you want
"mtime".

The find command is extremely powerful.  E.g.,
  find / -mtime +30

This will give you all files in the system that have been
modified over 30 days ago (i.e., 31+).

If you just want to look in the _current_directory_:  
  find . -maxdepth 1 -mtime +30

If you want to look at a particular file:  
  find /home/myfile -maxdepth 0 -mtime +30

If the file is listed, it was last modified 31+ days ago.
> How is that type of thing done in shell scripts.
Here's an example script that takes a list of files and moves
the files under /home/old (full path and attributes
preserved) if they are older than 30 days.

Syntax:
  fold30 file [file...]

Script:  

1:  [ "$1" == "" ] && exit 1
2:  mylist="$*"
3:  for myfile in ${mylist}; do
4:    if [ -f "${myfile}" ]; then
5:      if [ "`find ${myfile} -mtime +30`" != "" ]; then
6:        echo ${myfile} | cpio -pmdvu /home/old/${myfile}
7:        rm -f ${myfile}
8:      fi
9:    fi
A:  done

The main conditional on line 5 is what does the job.  If the
result of the find command is not an empty string, then the
name was returned and it is older than 30 days.  Now move it
to the same path under /home/old (using cpio) and remove the
original.

NOTE:  It will _not_ work if spaces are used in the paths,
that's something I've yet to see work correctly (I can never
get the "IFS" variable set to work proper in the loop) in
bash, so I professionally use tcsh instead.  Bash does not
seem to work with quotes in a loop like tcsh does, and the
Advanced Bash Scripting Guide (ABSG) is just _dead_wrong_ on
using quotes for most bash releases (although it works fine
across all tcsh versions I've used).


-- 
Bryan J. Smith                | Sent from Yahoo Mail
mailto:b.j.smith at ieee.org     |  (please excuse any
http://thebs413.blogspot.com/ |   missing headers)

Jerry Geis wrote:
> I am trying to find out how to tell if a given file is 30 days or older.
> How is that type of thing done in shell scripts.
>
> Thanks,
>
> Jerry
As with all things *nix, there is more than one way to do the job. You 
might start with this idea -- or not.  If you wanted to list all files 
in the current directory over 29 days old (you said "30 or older) this 
would do it:

$ find . -ctime +29   -print
   --OR-- those older than 29 days in your home directory
$ find ~ -ctime +29 -print  
   --OR-- to discover older rpms in the yum cache
$ find /var/cache/yum -ctime +29 -print | grep .rpm

Man find is your friend.  Don't be overwhelmed by its many options; 
start simple and build up to your goal.
>
>------------------------------------------------------------------------
>
>_______________________________________________
>CentOS mailing list
>CentOS at centos.org
>http://lists.centos.org/mailman/listinfo/centos
>  
>