Why doesn't Android keep track of the created and last accessed times as well as the last modified time for files in the file-system?
It doesn't store creation time because UNIX filesystems (generally speaking) simply don't store this anywhere, and Android doesn't seem to be any different. This Stack Overflow question has some discussion about this fact (you can ignore the fact that it's talking about Python - the answers are still relevant), and the man page for
stat describes what times are typically stored in the data structure.
As for the last accessed times...well it does keep track. Try
ls -l in any directory you have proper permissions for:
$ cd /sdcard/ cd /sdcard/ $ ls -l ls -l drwxrwxr-x system sdcard_rw 2011-04-27 14:31 LOST.DIR drwxrwxr-x system sdcard_rw 2011-04-27 14:31 DCIM drwxrwxr-x system sdcard_rw 2011-04-27 14:31 Android drwxrwxr-x system sdcard_rw 2011-04-27 16:14 glogs -rwxrwxr-x system sdcard_rw 49152 2011-05-27 16:04 AndroidBytes.txt drwxrwxr-x system sdcard_rw 2011-06-28 16:28 vim -rwxrwxr-x system sdcard_rw 0 2011-09-11 16:48 su-2.3.1-bin-signed.zip $
If you have
busybox you can also use the
stat command for more detailed info. It also lets you use some additional
ls flags like
man ls if you're not familiar with it). Here's a sample from
# stat databases stat databases File: "databases" Size: 2048 Blocks: 4 IO Block: 4096 directory Device: 1f06h/7942d Inode: 454 Links: 1 Access: (0771/drwxrwx--x) Uid: (10079/ app_79) Gid: (10079/ app_79) Access: 2011-09-29 09:07:44.000000000 Modify: 2011-09-29 09:07:44.000000000 Change: 2011-09-29 09:07:44.000000000 #