This tip is a give away. Everyone knows this, but for those who doesn’t or forgot…  here’s refresher…

Here’s a typical output of a file listing using `ls -l` on a directory:

[root@unix-box icons]# ls -l | more
total 636
-rw-r–r–    1 elizar root          246 Aug 26  2005 a.gif
-rw-r–r–    1 elizar root          242 Aug 26  2005 alert.black.gif
-rw-r–r–    1 elizar root          279 Aug 26  2005 alert.black.png
-rw-r–r–    1 elizar root          247 Aug 26  2005 alert.red.gif
-rw-r–r–    1 elizar root          298 Aug 26  2005 alert.red.png
-rw-r–r–    1 elizar root         2326 Aug 26  2005 apache_pb.gif
-rw-r–r–    1 elizar root         1385 Aug 26  2005 apache_pb.png
-rw-r–r–    1 elizar root          293 Aug 26  2005 a.png

When using the -l (dash ‘el’) option of ls, the output will display a more detailed listing of the files. Here you’ll see the file properties/permission (-rw-r–r–) the number of links, the owner of the file, the group of the user, file size, the date/time stamp and finally the file name. That’s 7 column.

Changing The Time Stamp Of A File

To change the time stamp of a file (the 6th column in the `ls -l` listing), we use the UNIX command touch.

From the Man Pag:

NAME
touch – change file timestamps

SYNOPSIS
touch [OPTION]… FILE…
touch [-acm] MMDDhhmm[YY] FILE… (obsolescent)

There are many options for the touch command, but the one I use fairly often is the -t option

       -t STAMP;    use [[CC]YY]MMDDhhmm[.ss]

Example:

 [root@unix-box icons]#  touch -t 200607161201 a.gif
[root@unix-box icons]# ls -l | more
total 636
-rw-r–r–    1 elizar root          246 Jul 16  2006 a.gif
-rw-r–r–    1 elizar root          242 Aug 26  2005 alert.black.gif

Other options that you  may find useful are -a (change access time only) -m (modification time only) and others. Consult the man page for more details

Cheers!