UNIX for Beginners Questions & Answers

What I know so far:
ls -A will list all files except those starting with a dot
ls -d will list all directories
ls -m will separate contents by commas
For getting crtimes use:
stat filename will give me the inode number
or
ls -i filename will give me the inode number

Code:

df -h

will give me the root partition
Then I can use:

Code:

sudo debugfs -R 'stat <inode>' root partion | grep crtime

to get the crtime

I need to know how to tie all of this together.

Moderator's Comments:

Please wrap your codes/samples in CODE and ICODE TAGS, as per forum rules.

Hi, try so

Code:

ls -cm

--- Post updated at 14:39 ---

what does this word mean "crtime" ?

--- Post updated at 14:50 ---

option -c in the ls command sorts files by the time of their last modification, but if this is a directory, then this is the time of the last modification of files in it.

Hi nezabudka,
For file systems that keep track of it, "crtime" refers to the time at which a file was created.

The last modification time (sometimes just called "mtime") of a directory is usually the time that the directory was created, the last time a link to a file was created in that directory, or the last time a link to a file was removed from that directory, whichever occurred most recently. But, of course, it can also be set to an arbitrary time at least by the C language futimens( ), utimensat( ), and utimes() functions. Changing the size of an already existing file in a directory does not change the modification time of any directory that contains that file.

Note that if a file has multiple hard links (not symlinks), that single file can exist in more than one directory.

I won't address all points because i am a bit short on time today. It suffices for addressing one point, though:

No. What -d does is it will not follow a directory. That means if you use a wildcard (or, more precisely, a "file glob") like this:

Code:

ls foo*

The shell will - prior to calling ls - expand the glob into a list of filesystem items matching this name. filesystem items can be all sorts of things but we are here interested only in files and directories. So, lets say for example that there are three such items, fooA, fooB and fooC. If these are all files the output would simply be:

Code:

$ ls foo*
fooA fooB fooC

So far, so good. But what happens if one of these is a directory? In this case the directory would be followed, which means all the files in this directory would be displayed too, i.e.

Code:

$ ls foo*
fooA

fooB:
 fileinfooB1 fileinfooB2

fooC:
fileinfooC1 fileinfooC2

Notice that this is not the fault of the shell: the shell still generates only the list of the three filenames but ls, when it sees the name of a directory, will list the files in that directory. In this case obviously fooB and fooC must be directories. This makes sense because when you enter

Code:

ls /usr

You usually want to see what is in that directory, not just the directory name itself. But sometimes one would not want that and this is why -d exists. It will make the ls NOT follow the directories and display their files but only there names as if they would be normal files.

I hope this helps.

bakunin

I have been able to make some progress on the problem. I found a partial solution, but I can't
post the links yet.

Here is the code:

Code:

xstat() {
  for target in "${@}"; do
    inode=$(ls -di "${target}" | cut -d ' ' -f 1)
    fs=$(df "${target}"  | tail -1 | awk '{print $1}')
    crtime=$(sudo debugfs -R 'stat <'"${inode}"'>' "${fs}" 2>/dev/null | 
    grep -oP 'crtime.*--\s*\K.*')
    printf "%s\t%s\n" "${crtime}" "${target}"
  done
}

I made a change to the printf statement to:

Code:

printf "%s %s, " "${crtime}" "{target}"

With this change I get a comma separated list of crtime (creation time) and names of the files
in the current directory.
The problem with this is that the files are not sorted by crtime.

I found code that solved the sort problem, but I don't know how to change the printf statements to get a comma separted list of crtime and name:

Here is the code I found:

Code:

crtime-at() {
for target in *; do
inode=$(ls -di "${target}" | cut -d ' ' -f 1)
fs=$(findmnt -n -o SOURCE --target "${target}")
crtime=$(sudo debugfs -R 'stat <'"${inode}"'>' "${fs}" 2>/dev/null | 
grep -oP 'crtime.*--\s*\K.*')
crtime=$(date -d "${crtime}" +%Y-%m-%d\ %H:%M:%S)
printf "%s\t%s\n" "${crtime}" "${target}" >> /tmp/crtime
done
crtime=$(sort -t$'\t' -k1 -n /tmp/crtime)
printf "${crtime}"
rm /tmp/crtime
echo
}

The second program sorts by crtime, but I don't know enough about
Bash programming to figure out how to get i displayed as a comma separated list.

If anyone understands this code and has the time to explain it line by line, I believe it
will help me as well as the community.

Thanks for all the responses.

Charles

Hmm I clearly must be missing something. Late to the party again...
stat command will do what you want without sudo.

%w is the human readable format for crtime
%W is the format for epoch seconds for crtime -- which you use for sorting.

Code:

$ stat --format "%W, %w, %n" t.lis
1440371010, 2015-08-23 17:03:30.103891500 -0600, t.lis

So, this may be what you want: get three fields, sort by field one (crtime), print readable crtime and file name with comma separated data. Change the awk printf to what you want. Seemed a bit confusing to me.

Code:

cd /path/to/files
 stat --format "%W, %w, %n" * | sort -n -k1 | awk -F ',' '{ printf("%s, %s", $2, $3)}' > /path/to/output/file

This looked promising and even the manpage for stat seems to agree, but when I enter the commands in ubuntu, all I get is:
-, filename
for each file.

Maybe I'm doing something wrong?