[MacOS] Renaming output files

[shape]

I tried using Save to Disk and all the saved files still truncate. And not by just a few characters but by several lines that macOS allows me to add manually to the filename. Is there a setting that is causing it to truncate?

The “Automatically convert added books...” option in “Add Books” -> "Control the adding of books" -> "Adding actions" works so well that it's a shame not to be able to use this and also be able to control the filename output.

[BetterRed]

Originally Posted by shape

I tried using Save to Disk and all the saved files still truncate. And not by just a few characters but by several lines that macOS allows me to add manually to the filename. Is there a setting that is causing it to truncate?

The “Automatically convert added books...” option in “Add Books” -> "Control the adding of books" -> "Adding actions" works so well that it's a shame not to be able to use this and also be able to control the filename output.

See ==>> Save to disk

You can control the file name and folder structure of files saved to disk by setting up a template in Preferences → Import/export → Saving books to disk. Also see The calibre template language

BR

[shape]

Thanks, but I don't see anything about filename truncation. The default naming template is sufficient but I don't see anything in the prefs or the manual about how to save the complete title & author names without truncating them.

[BetterRed]

It would help of you posted some screen shots as evidence of your claims that save to disk truncates your file names.

The Save to disk template defines how to construct save to disk paths and file names from the metadata.

Example - in the following screenshot you see a Russian version of Tolstoy's War and Peace in my Test library and the contents of the library book folder - note the transformation of the title and author names from Cyrillic into Latin-1.



These are my Save to disk preferences:



When I do a Save to disk this is what I get in my Saved Books folder :



Unfortunately I don't have an example of a truncated library file name - they a usually caused by subtitles, straplines, series names etc concatenated with the title in the title column.

BR

[shape]

Sure, I can post screenshots. Many of the ones that truncate actually do have the series name in the title in parenthesis. I didn't know this was a factor. But if I remove the parenthesis in Calibre and paste in more text it still cuts off the names of files and folders when saving to disk.

Here’s an example book title: “Enemy of the People: The Untold Story of the Journalists Who Opposed Hitler” by Terrence Petty. This is how it saves using the default “Save to Disk” template in Preferences w/ the latest Calibre 5.40 for macOS. In the 2nd image all folder/file names are truncated in the middle for some reason, even with the author folder which isn’t due to potentially having too many characters:

[BetterRed]

Originally Posted by shape

Sure, I can post screenshots. Many of the ones that truncate actually do have the series name in the title in parenthesis. I didn't know this was a factor. But if I remove the parenthesis in Calibre and paste in more text it still cuts off the names of files and folders when saving to disk.

Here’s an example book title: “Enemy of the People: The Untold Story of the Journalists Who Opposed Hitler” by Terrence Petty. This is how it saves using the default “Save to Disk” template in Preferences w/ the latest Calibre 5.40 for macOS. In the 2nd image all folder/file names are truncated in the middle for some reason, even with the author folder which isn’t due to potentially having too many characters:

Attachment 193182

Attachment 193183

I use Windows 10, and I can save the same title with no truncation - even though Windows has a reputation of imposing greater restrictions on file system path lengths, and allowable characters than MacOS or Linux.

FWIW I would put the subtitle into a separate custom column as shown in the attached screen shots. The replacement of the ':' with '_' is because Windows does not allow < > : " / \ | ? * in file names.

I am going to put your issue in to its own thread and mark it as MacOS.

BR

[kovidgoyal]

Filenames have limited size. Dont try to shoehorn unlimited data into them.

[shape]

Originally Posted by BetterRed

The replacement of the ':' with '_' is because Windows does not allow < > : " / \ | ? * in file names.

It’s the same thing with certain special characters on Mac actually, including the colon but not the underscore. I would have liked to get the filenames to save without truncating before customizing the template, but how do I add the subtitle field?

@kovidgoyal: But why are they being cut off in the middle, and why would the author's name also be truncated in the folder name as "Petty,rrence"? I also explained that on Mac I can type in extra lines of text (dozens of additional characters), so the filename allowed by the OS is not the limitation.

[shape]

The name cutting off as "Petty,rrence" looks buggy. Does a complete author name really qualify as unlimited data or were you referring to something else?

[BetterRed]

Originally Posted by shape

It’s the same thing with certain special characters on Mac actually, including the colon but not the underscore. I would have liked to get the filenames to save without truncating before customizing the template

What do you have in the Save to Disk template ?

And what is the path into which you are saving the books, try saving to a folder that's not deep in the file system hierarchy - e.g I am saving to:

C:\Users\<--my  name-->\Desktop\Saved Books

Originally Posted by shape

…but how do I add the subtitle field?

Preferences->Add your own columns:



BR

[DNSB]

Originally Posted by shape

@kovidgoyal: But why are they being cut off in the middle, and why would the author's name also be truncated in the folder name as "Petty,rrence"? I also explained that on Mac I can type in extra lines of text (dozens of additional characters), so the filename allowed by the OS is not the limitation.

calibre enforces a maximum path length regardless of OS. While APFS allows up to 255 characters for the filename length and a maximum path length of 1024, you run into the maximum path length (directory names plus filename) at a lot less than 1024 bytes with many OS (Windows for example), a common limit is 255 characters. Since calibre is multi-OS, it uses the shortest path length of the supported OS.

With Montery 12.3.1, here's what the OS reports as the limits:

davidb@Davids-VMMac ~ % getconf NAME_MAX /
255
davidb@Davids-VMMac ~ % getconf PATH_MAX /
1024

What you are showing is a path length of ~177 characters. If you have the Petty,rrence directory in the root of your hard drive, that's all she wrote. As it is, when I look at my Mac VM, the path to a calibre library is:

/Users/davidb/calibre/Calibre Library/

Adding this to your path, I get:

/Users/davidb/calibre/Calibre Library/Petty,rrence/Enemy of the People: The Untold Stthe Journalists Who Opposed Hitler/Enemy of the People_ The Untold Story of the Journalists Who Opposed Hitler - Terrence Petty.kfx

Depending on where you are saving to disk and the length of your user name, your path may be longer or shorter but likely longer.

Personally, I place subtitles into a column just for them and only use the first entry in the author(s) and author sort to keep lengths shorter. The author bits are more intended for anthologies where you can have multiple authors and path lengths rapidly get out of control.

Since I use mostly Kobo eReaders, I can send subtitle, series & multiple authors without needing to store them in the filename.

As Kovid said, try to keep filenames short. Write your book in the file and not in the filename.

[chaley]

You can control where/how truncation happens using the built-in template function shorten(val, left chars, middle text, right chars).

The function documentation is:

Return a shortened version of val, consisting of `left chars` characters from the beginning of val, followed by `middle text`, followed by `right chars` characters from the end of the string. `Left chars` and `right chars` must be integers. For example, assume the title of the book is `Ancient English Laws in the Times of Ivanhoe`, and you want it to fit in a space of at most 15 characters. If you use {title:shorten(9,-,5)}, the result will be `Ancient E-anhoe`. If the field's length is less than left chars + right chars + the length of `middle text`, then the field will be used intact. For example, the title `The Dome` would not be changed.

The idea is that if filenames can be truncated because of path length then *you* decide where the truncation occurs. This ensures that the resulting values are predictable and consistent.

You can also choose to use only the first author, not all of them.

For example, this template uses the first 30 characters of the first author's name and the first 120 characters of the title, separated by a dash.

{authors:'shorten(sublist($, 0, 1, '&'), 30, '', 0)'} - {title:shorten(120,,0)}

You can get more exotic and use the first 15 characters of the first N authors separated however you want, then the title shortened however you want. This is easiest done with a General Program Mode template using a 'for' statement to loop through the authors. For example, the following template includes the first 4 authors shortened to 15 characters then a dash then the title shortened to 100 characters.

program:
	res = '';
	sep = '';
	for a in sublist($authors, 0, 4, '&') separator '&':
		res = res & sep & shorten(a, 15, '', 0);
		sep = ' & '
	rof;
	res & ' - ' & shorten($title, 100, '', 0)

NB: this template works in calibre 5.39 or later because it used the new '&' concatenation operator. If necessary you could back up to V5.10 (or so) by using the strcat() function.