Get offset of current buffer in vim (in particular, via python scripting)

Question

i want to get the offset of

1. the current cursor position
2. the current selection range

in vim, beginning from the start of the file. I do this in python, so hints how to do it with vim's python scripting would be very helpful.

I have used vim.current.. before for doing scripting, but it uses lines and columns rather than a general offset.

Would i have to calculate the amount of all preceding line lengths + the current row, or is there a simpler method ?

Answer 1

If your vim is compiled with the +byte_offset option, then in a Python script after the usual import vim, you can use, e.g.:

vim.eval('line2byte(line("."))+col(".")')

to get the byte offset from start of file of the cursor position, and similarly for other marks. More generally, if you have a line/column pair this (assuming +byte_offset is how your vim was compiled with) is the way to get a byte offset (there's also a byte2line function to go the other way).

While the vim module does make a lot of functionality available directly to Python scripts in vim, I've found that vim.eval and vim.command are often the handiest (and sometimes the only;-) way to get in just as deep as needed;-). Oh, and I always try to have a vim compiled with +justabouteverything whenever I can;-).

Answer 2

You may also want to look at the statusline setting. This will add the bye offset to the statusline:

set statusline+=%o

See :h statusline

Just be careful because the default statusline is blank, and by appending the %o to it, you loose all the defaults.