[SOLVED] The behaviour of the tree command "-t" option

incans · 2025-04-04 15:01:38

I'm working on a script that processes files under a specified root directory. The tree command is ideal for this.

The specific command I have ended up with is-

tree -afugpiQDt --timefmt='%s' /dirpath

Which produces output like-

[drwxrwsr-- username    admin    1743552894]  "/dirpath"
[drwxrwsr-x username    admin    1740576183]  "/dirpath/archive"
[drwxrwsr-x username    admin    1739765107]  "/dirpath/archive/Admin"
[-rw-rw-r-- username    admin    1288133839]  "/dirpath/archive/Admin/Serial Numbers Games.txt"
[-rw-rw-r-- username    admin    1292952813]  "/dirpath/archive/Admin/Serial Numbers Apps.txt"
[-rw-rw-r-- username    admin    1345070773]  "/dirpath/archive/Admin/Thumbs.db"
[-rw-rw-r-- username    admin    1576249716]  "/dirpath/archive/Admin/Serial Numbers.xlsx"
[-rw-rw-r-- username    admin    1576671892]  "/dirpath/archive/Admin/Software List.ods"
[-rw-rw-r-- username    admin    1576703734]  "/dirpath/archive/Admin/Software List.xlsx"
[-rw-rw-r-- username    admin    1660600694]  "/dirpath/archive/Admin/Serial Numbers.ods"
[-rw-rw-r-- username    admin    1661344145]  "/dirpath/archive/Admin/Serial Numbers OS.csv"
[-rw-rw-r-- username    admin    1661344258]  "/dirpath/archive/Admin/Serial Numbers OS.txt"
[drwxrwsr-x username    admin    1739765059]  "/dirpath/archive/Admin/Applications"
[-rw-rw-r-- username    admin    1050511481]  "/dirpath/archive/Admin/Applications/Xara X.html"
[-rw-rw-r-- username    admin    1058037173]  "/dirpath/archive/Admin/Applications/Xara_Gallery_CD.reg"
[-rw-rw-r-- username    admin    1058044314]  "/dirpath/archive/Admin/Applications/Xara_Gallery_Disk.reg"
[-rw-rw-r-- username    admin    1081720124]  "/dirpath/archive/Admin/Applications/Xara User Defaults.reg"
[-rw-rw-r-- username    admin    1120521729]  "/dirpath/archive/Admin/Applications/XaraX Precision.txt"
[-rw-rw-r-- username    admin    1201454348]  "/dirpath/archive/Admin/Applications/Xara_Gallery_Merge.reg"
[-rw-rw-r-- username    admin    1296488453]  "/dirpath/archive/Admin/Applications/Xara enable thumbnails Win7 64.TXT"

What's confusing me with this is-

The -t option specifies sort by file modified time.
The -timefmt specifies printing the file modified time as a unix timestamp.

But the output of tree is NOT a list of paths with either monotonically increasing or monotonically decreasing modified timestamps(?) Instead the list still appears to be sorted by the full path string.

Note: I tried adding the -U option, which is supposed to suppress the default sorting, but this makes no difference.

I was hoping to generate a file list in "last modified time" order (ideally, descending), so I can process the files one at a time and when I hit a cutoff time of (say) one hour ago, stop processing knowing I have dealt with all the recently changed files.

Have I misunderstood how the options (especially -t) of the tree command are supposed to work?

Last edited by incans (2025-04-05 19:53:36)

seth · 2025-04-04 15:36:10

bash 101: Do not parse the output of ls. Same goes for tree.

You want to use find which can filter by timestamps and pass the match to some exec.

incans · 2025-04-04 16:01:18

seth wrote:

bash 101: Do not parse the output of ls. Same goes for tree.
You want to use find which can filter by timestamps and pass the match to some exec.

I'm not using bash.
I am aware I could use find. However I want to have access to the full file list (partly so I have the full count for reporting purposes), so I don't want to pre-filter the list with the "since time X" rule. Also, I have some include and exclude rules to apply to the file set, which results in either a horribly complex find command line and/or multiple find passes over the same file tree. By comparison, having a flat file list and then applying the complex rules in a loop over that list is easier to both write and test.
What I want, at this point, is an answer to the original question. Positive advice is always welcome, "don't start from here" is rather less helpful.

seth · 2025-04-04 17:16:37

Look at lines 4&5 of your output. How are they sorted?
tree still produces a hierarchical structure ("tree") and sorting happens within that.
You could pipe it through sort or use ls -R except all of that is categorically wrong no matter the shell.
Use find.

incans · 2025-04-04 19:06:23

seth wrote:

Look at lines 4&5 of your output. How are they sorted?
tree still produces a hierarchical structure ("tree") and sorting happens within that.
...
Use find.

Right. So tree always emits a valid tree structure, and then applies sort rules to the peer-level items within a directory. Ok, that makes sense, and is useful information. Thank you.

seth · 2025-04-04 19:53:01

Please always remember to mark resolved threads by editing your initial posts subject - so others will know that there's no task left, but maybe a solution to find.
Thanks.

Arch Linux

#1 2025-04-04 15:01:38

[SOLVED] The behaviour of the tree command "-t" option

#2 2025-04-04 15:36:10

Re: [SOLVED] The behaviour of the tree command "-t" option

#3 2025-04-04 16:01:18

Re: [SOLVED] The behaviour of the tree command "-t" option

#4 2025-04-04 17:16:37

Re: [SOLVED] The behaviour of the tree command "-t" option

#5 2025-04-04 19:06:23

Re: [SOLVED] The behaviour of the tree command "-t" option

#6 2025-04-04 19:53:01

Re: [SOLVED] The behaviour of the tree command "-t" option

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