How to copy date created to date modified ubuntu 22.04

I am using ubuntu 22.04 LTS and I want to know if the date created on ubuntu can be copied to date modified? I think I've read that the date created on ubuntu isn't actually the date created even though the label 'date created' is in Nautilus, rather it's the ctime (date changed). Is this correct ? How can I copy the date changed or 'date created' into date modified?

Thanks!!

You are right … ctime is the file's last status(i.e. meta data) change time.

However, in recent kernels, the support of the system call statx() is added ... That, when a file is queried with e.g. stat file, should return some extended file attributes including btime which is the birth/creation time of that file (Check first with stat file to see if birth time is reported) ... A quick check on Ubuntu 22.04 shows that stat indeed uses statx() to get the btime ... See for example:

$ strace -e statx -v -s 0 stat filename
statx(AT_FDCWD, "filename", AT_STATX_SYNC_AS_STAT|AT_SYMLINK_NOFOLLOW, STATX_ALL, {stx_mask=STATX_ALL|STATX_MNT_ID, stx_blksize=4096, stx_attributes=0, stx_nlink=1, stx_uid=1000, stx_gid=1000, stx_mode=S_IFREG|0664, stx_ino=22022834, stx_size=0, stx_blocks=0, stx_attributes_mask=STATX_ATTR_COMPRESSED|STATX_ATTR_IMMUTABLE|STATX_ATTR_APPEND|STATX_ATTR_NODUMP|STATX_ATTR_ENCRYPTED|STATX_ATTR_AUTOMOUNT|STATX_ATTR_MOUNT_ROOT|STATX_ATTR_VERITY|STATX_ATTR_DAX, stx_atime={tv_sec=1679481498, tv_nsec=733858313} /* 2023-03-22T13:38:18.733858313+0300 */, stx_btime={tv_sec=1679481214, tv_nsec=228264332} /* 2023-03-22T13:33:34.228264332+0300 */, stx_ctime={tv_sec=1679481498, tv_nsec=733858313} /* 2023-03-22T13:38:18.733858313+0300 */, stx_mtime={tv_sec=1679481498, tv_nsec=733858313} /* 2023-03-22T13:38:18.733858313+0300 */, stx_rdev_major=0, stx_rdev_minor=0, stx_dev_major=8, stx_dev_minor=2}) = 0
  File: filename
  Size: 0           Blocks: 0          IO Block: 4096   regular empty file
Device: 802h/2050d  Inode: 22022834    Links: 1
Access: (0664/-rw-rw-r--)  Uid: ( 1000/  ubuntu)   Gid: ( 1000/  ubuntu)
Access: 2023-03-22 13:38:18.733858313 +0300
Modify: 2023-03-22 13:38:18.733858313 +0300
Change: 2023-03-22 13:38:18.733858313 +0300
 Birth: 2023-03-22 13:33:34.228264332 +0300
+++ exited with 0 +++

Therefore, you should be able to copy the creation time of a file to replace its modification time with something like this:

touch -m -d "$(stat -c '%w' file)" file

Or to replace both access and modification times add the -a option to touch as well … or drop the -m option from touch as it should then default to both.

Or, you can do the same for all the files in the current working directory with something like this:

for f in *
  do
    [ -f "$f" ] && touch -m -d "$(stat -c '%w' "$f")" "$f"
  done