topic Re: difference b/w change and modify terms in Operating System - Linux

difference b/w change and modify terms

monu_1 — Tue, 03 Jul 2007 03:21:20 GMT

Dear Experts,

I am little bit confuse with the term modify and change in the output of stat command.

Please clear me about same.

Thanks,
MKS

Re: difference b/w change and modify terms

Steven E. Protter — Tue, 03 Jul 2007 07:18:54 GMT

Shalom,

Please post the command you used and at least a sample of the output.

stat has many options, at least on Red Hat ES 5.

SEP

Re: difference b/w change and modify terms

monu_1 — Tue, 03 Jul 2007 07:27:28 GMT

Hi Shalom!

The command is

# Stat

Regards,
MKS

Re: difference b/w change and modify terms

James R. Ferguson — Tue, 03 Jul 2007 07:49:08 GMT

Hi:

The 'stat' structure maintains three timestamps: an 'atime'; a 'ctime' and an 'mtime'. These timestamps are in units of of Epoch seconds.

The 'atime' represents the last access timestamp of a file or directory.

The 'mtime' represents the last time a file or directory was *modified*; that is, the last time the file was written into. The 'mtime' is coincidently equalivalent to a "creation" moment only when a file (or directory) is first instantiated. There is no creation timestamp.

The 'ctime' is the last time a *change* of permission, ownership or name occured. Changeing any of these attributes does *not* alter the 'mtime' since the contents of the file are not modified.

Regards!

...JRF...

Re: difference b/w change and modify terms

Maaz — Wed, 04 Jul 2007 07:19:46 GMT

stat

what i found is that, whenever the contents of files are change(file edit), both the "Modified", and "Change" paramete updates

But when you just change the permission/ownership... the "Change" parameter updates only.

Regards

Re: difference b/w change and modify terms

James R. Ferguson — Wed, 04 Jul 2007 07:48:31 GMT

Hi (again):

> what i found is that, whenever the contents of files are change(file edit), both the "Modified", and "Change" parameter updates

That is expected since the file's inode (containing the information retrieved by stat()') would be updated. The 'ctime' represents the inode's last change time, and another field of the inode is the size of a file.

Regards!

...JRF...