List file creation date in bash

nvn

How do you list creation date of a file in linux bash? I want to find creation date of some files, not just modification date. Thanks.

jtbell

According to 'man ls' on Mac OS, 'ls -Ul' shows the file-creation time instead of the last-modification time, in the long-format output.

nvn

That does not appear to work on GNU bash; i.e., "ls -Ul" does not appear to give file creation date on GNU bash (redhat linux). Any other ideas?

jim mcnamara

It depends on the file system. Traditionally UNIX file systems like ffs, ufs, and ext2 only kept mtime, ctime and atime: mtime == modifocation time, ctime == inode change time, and atime == access time.

Some newer filesystems have file creation times:
ufs2 → st_birthtime
zfs → crtime
ext4 → crtime
btrfs → otime
jfs → di_otime

Is one way to show it. Since ls is part of coreutils you have to have an ext4 filesystem (for example) mounted with the correct options and you need a recent version coreutils.

If your ls man page does not show an option then you are stuck with stat, which had crtime support earlier.

This is not an "idea" - this is how the thing works. Check to see what filesystems you have.

lists exactly all mount options, filesystems, etc. Harder to read. This is a file so user the less command.

nvn

The mount command appears to say the file system is "ext3 (rw,nodev)." My stat command does not have a %W nor %w option. If I issue only the command "stat filename," it lists the following. What should I try now?

Access: <date/time>
Modify: <date/time>
Change: <date/time>

jim mcnamara

Um. the polite term is you are out of luck.

An answer that is constructive but probably NOT what you want to hear:
1 download the package, rpm or whatever your linux calls it, for ext4 support.
2. install ext4.
3. mount the ext4 filesystem. Follow the guidelines for enabling crtime support.
4. All files written onto the new filesystem will then have creation dates.
Next.
1. download and install the very latest coreutils for your linux. Your commands now support creation times.

Don't do all that unless you are really masochistic.

Without using the word creation date (or time) please tell me what you are actually trying to do. Where there is a shell there is a way.

nvn

I am not that masochistic.

Because I want to know when some content was initially created, I do not know how to explain it without using some of the words in post 1. Anyway, thank you very much for the help.

jim mcnamara

ctime will do for most of what creation time does.

Unless you use these commands a lot: chmod, chown, setfacl
ctime is completely identical to creation time as kept by windows.

Based on your questions I would guess that chmod, chown, and setfacl are not a standard part of your everyday linux usage, so chances are really good this will do what you want.

nvn

No, "ls -ltc" shows, e.g., "2012-11-04" on almost all of my files, or a large percentage of them, even though I did not change anything in or about those files in that time frame. Therefore, that command is not working for giving me any indication of file creation date. But thanks again for all the information.

gsal

Quick question...

forget about GNU bash for a moment...can you get creation time for your files any other way?

just trying to figure out if it is even being preserved by your OS or available with your FS

can you see creation time using the file manager? (nautilus? or whatever?)

if it is available, then, I am sure there is a way to retrieve it...in the worst case, you may need to figure out what the file manager is doing to get it.

any way, just checking, just a thought

AlephZero

ctime gives the time when the inode (i.e. the directory entry that points to the file) was last changed. mtime gives the time when the file was last changed.

ctime MIGHT be the time when the file was first created, but there is no guarantee, and no way to find out if it is or isn't AFAIK.