Is there a good emacs mode for displaying and editing huge delimiter separated files?

Question

I've been searching without finding for a while for a mode that makes editing huge tab/comma/colon-separated files easy. I've been wanting a mode that ensures that columns always line up, just like org-mode tables. I know I can easily turn the whole file into an org-mode table and then turn it back when I'm done, but that gets really slow with huge files, and is a hassle for quick edits (there's also the problem of what happens if a field contains a vertical bar). So does anyone know of either a mode or a built-in function/variable I can use so that I can get a file like

col1\tcol2\tcol3
very long column1\tcol2\tcol3

displayed like

col1               col2  col3
very long column1  col2  col3

? (perhaps with some color lining the separator)

Answer 1

Perhaps you could tell us what you've already found and rejected?

If you've been searching, then you must surely have seen http://emacswiki.org/emacs/CsvMode ? You don't mention it, or say why it wasn't any good, though.

SES (Simple Emacs Spreadsheet) might be a useful approach:

C-hig (ses) RET

You can create a ses-mode buffer and yank tab-delimited data into it (that's the import mechanism).

It's probably more hassle than you were after, though, and I'm not sure how well it will perform with "huge" files.

Answer 2

Try csv-mode, which works in at least Emacs 24.

You can set the variable csv-separators to change the separator if you do not use the default one (comma).

See EmacsWiki.

Answer 3

As @choroba mentioned, use csv-mode. To answer your question specifically:

• Make sure your separator is in csv-separators, which for example you can set with

  (setq csv-separators '("," "    "))
  

• Use csv-align-fields (default keybinding C-c C-a) to line up the field values into columns.

@unhammer's comment about aligning only visible lines is great. Their code properly indented:

(add-hook 'csv-mode-hook
          (lambda ()
            (define-key csv-mode-map (kbd "C-c C-M-a")
              (defun csv-align-visible (&optional arg)
                "Align visible fields"
                (interactive "P")
                (csv-align-fields nil (window-start) (window-end))
                )
              )
            )
          )

Answer 4

There is pretty-column.el, which I found in Group gnu.emacs.sources years ago (it was added in 1999). That group is now blocked, by Google. I just used pretty-column.el on a ~5000 line tab-separated text file that Org mode choked on (Org mode has a 999 line limit on converting such a file--for that reason). Added in edit: This seems to now be called delim-col.el (see this Emacs Wiki entry); the author is the same person.