Problem with template and save to disk

[elfnor]

I'm trying to follow this guide

https://manual.calibre-ebook.com/sub_groups.html

and have successfully set up a hierarchical column #folder and entered the template

{#folder:subitems(0,1)||/}{title} - {authors}

in Preferences -> Saving books to disk

When I save to disk I get folders that look like spelling errors that I swear are not in my custom column

 $ ls
_catalog  ficion  fiction  fion  fn  nonfiction

I have entries in my #folder column that go three deep such as "fiction.sff.shortstories" but none like "ficion". The tag browser works as expected and shows none of the odd tags.

All of the wrong folders have some books, but I can't yet see anything special or odd about these books or their metadata.

I attempted to write a template to Save to Disk in a 3 deep folder structure, which has similar errors.

Calibre 3.26.1 running Linux Mint 19

[Adoby]

Take some of the books in the weird folders and add them to a new empty library (create it with the same structure as the old). Examine the books there and save to disk from there and see if you can reproduce it.

If you can't reproduce it then your library is corrupt. The library maintenance tools may fix it.

Or make a copy of a book with the problem and post here.

You can't post a copyrighted book so you have to use a public domain book and transfer the problem metadata to it:

Work in the new test library (so you don't delete the real book!)

I believe you can use a public domain epub book and simply drop it on the details pane. Then it should replace the existing epub or add a epub format book to the title. Save to disk again to write metadata to the epub and post here...

[davidfor]

@elfnor: You are probably hitting a path-length problem. When creating a file, calibre has to make sure that it has a legal file name. This includes making sure the full path is not to long. In Windows, the limit is 256 or 260 characters and I don't remember if similar limits are used on the other platforms.

When the path is to long, and this includes the directory you are saving to, calibre fiddles with the parts of the path to reduce the overall length. The examples you have are the type of changes I have seen.

[elfnor]

@davidfor is right. All the books in the shortened folders are books of short stories with many multiple authors.

Only including the first author in the file name works:

{#folder:subitems(0,1)||/}{title} - {authors:sublist(0,1,&)}

For my 3 deep hierarchy of tags in my custom column #folder this works:

{#folder:subitems(0,1)||/}{#folder:subitems(1,2)||/}{#folder:subitems(2,3)||/}{title} - {authors:sublist(0,1,&)}

Thanks

[chaley]

@elfnor: the "shorten" template function can help control path shortening. You would use the function to ensure that no name segment is longer than some N. Note that you would need to use Template Program Mode because you would need to use subfunctions.

[Adoby]

Originally Posted by elfnor

Calibre 3.26.1 running Linux Mint 19

Ubuntu (and Mint I assume) typically use the ext4 filesystem with around 4096 char max path length. What filesystem do you use?

Or does calibre enforce short paths in Linux as well?

Filenames in ext4 must fit in 255 chars.

[theducks]

Originally Posted by Adoby

Ubuntu (and Mint I assume) typically use the ext4 filesystem with around 4096 char max path length. What filesystem do you use?

Or does calibre enforce short paths in Linux as well?

Filenames in ext4 must fit in 255 chars.

I believe there is only one enforcement rule so to allow moving a Library between OS (being aware of CaSe issues)

[kovidgoyal]

Path length restrictions are OS dependent. IIRC on non window OSes they are set to about twice what they are on windows.

[vorcisrdr]

Originally Posted by elfnor

@davidfor is right. All the books in the shortened folders are books of short stories with many multiple authors.

Only including the first author in the file name works:

{#folder:subitems(0,1)||/}{title} - {authors:sublist(0,1,&)}

For my 3 deep hierarchy of tags in my custom column #folder this works:

{#folder:subitems(0,1)||/}{#folder:subitems(1,2)||/}{#folder:subitems(2,3)||/}{title} - {authors:sublist(0,1,&)}

Thanks

Sorry for resurrecting the thread...

I'm about to test this because I was getting garbled second folder names... I use the same 'genre' style system as described in the doco.

[sterned]

Originally Posted by kovidgoyal

Path length restrictions are OS dependent. IIRC on non window OSes they are set to about twice what they are on windows.

not anymore with windows 10 I have very long path names more than 255 now.

[kovidgoyal]

Originally Posted by sterned

not anymore with windows 10 I have very long path names more than 255 now.

yes and try accessing those really long paths using windows explorer or 90% of windows software. Windows has supported long paths for over a decade, but in a half assed way because they want to keep backward compatibility, that can lead to those files easily becoming inaccessible for non computer savvy users. As such calibre is definitely not going to support creating them.