Is there any way to use chown/chgrp without modifying the last modified date?

Question

I'm recovering files from an old hard drive and I need to keep the last modified date from the drive. The reason they are updating is because I need to change the ownership of the files to a new user.

Solution

The mtime (file modification time) shouldn't change when the owner is changed (nor should the atime or access time). That would be a change in the inode information, reflected in the ctime field.

If you find that on your system, chown(2) (or chown(1) and chgrp(1)) do change the mtime or atime and you're concerned about preserving both mtime and atime, then you'll need to write code to collect the current times (using stat(2) or stat(1)), and reinstate them (using utimes(2) or touch(1)).

AFAIK, you cannot control the setting of the ctime. If the inode changes, the system records the time it changed and doesn't allow you to change that.

Comments

[nalply]

This would be suspicious. Imagine a hacker or a rootkit disguising its accesses.

[rahul]

Hmm, interesting. I assumed that the chown and chgrp commands would be the modifiers on the time. The only other action performed on the files was a transfer from a hard drive to a server using ftp via Filezilla. Would this cause the time change?