Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

List file creation date in bash

  1. Nov 12, 2012 #1

    nvn

    User Avatar
    Science Advisor
    Homework Helper

    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.
     
  2. jcsd
  3. Nov 12, 2012 #2

    jtbell

    User Avatar

    Staff: Mentor

    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.
     
  4. Nov 12, 2012 #3

    nvn

    User Avatar
    Science Advisor
    Homework Helper

    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?
     
    Last edited: Nov 12, 2012
  5. Nov 12, 2012 #4

    jim mcnamara

    User Avatar

    Staff: Mentor

    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

    Code (Text):

    stat -c %W filename
    stat -c %w filename
     
    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
    Code (Text):
    mount -p
    to see what filesystems you have.

    Code (Text):

    /etc/mnttab
     
    lists exactly all mount options, filesystems, etc. Harder to read. This is a file so user the less command.
     
    Last edited: Nov 12, 2012
  6. Nov 12, 2012 #5

    nvn

    User Avatar
    Science Advisor
    Homework Helper

    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>​
     
    Last edited: Nov 12, 2012
  7. Nov 12, 2012 #6

    jim mcnamara

    User Avatar

    Staff: Mentor

    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.
     
  8. Nov 12, 2012 #7

    nvn

    User Avatar
    Science Advisor
    Homework Helper

    I am not that masochistic. :biggrin:

    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.
     
  9. Nov 12, 2012 #8

    jim mcnamara

    User Avatar

    Staff: Mentor

    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.

    Code (Text):

    cd /path/to/content
    ls -ltc *.whatever  # files in order most recent -> oldest and shows ctime
    ls -ltrc *.something  # files in order oldest -> most recent and shows ctime
     
    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.
     
  10. Nov 12, 2012 #9

    nvn

    User Avatar
    Science Advisor
    Homework Helper

    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.
     
  11. Nov 13, 2012 #10
    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
     
  12. Nov 13, 2012 #11

    AlephZero

    User Avatar
    Science Advisor
    Homework Helper

    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.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: List file creation date in bash
  1. C++ .dll file Creation (Replies: 2)

Loading...