How to get the content between two specific lines in vimscript?

Question

How can I write a function to get the content between mark 1 and mark 2 for further processing? mark can be a string, or a function call, it doesn't matter.

mark 1

foo1
foo2
foo3

mark 2

Answer 1

See :h getbufline():

getbufline({expr}, {lnum} [, {end}])

Return a List with the lines starting from {lnum} to {end} (inclusive) in the buffer {expr}. If {end} is omitted, a List with only the line {lnum} is returned.

To get the line numbers you're looking for you can use :search() for example. See :h search().

For example in this file:

mark 1

foo1
foo2
foo3

mark 2

The command:

echo getbufline(bufnr('%'), 1, 7)

Will return the following list:

['mark 1', '', 'foo1', 'foo2', 'foo3', '', 'mark 2']

You might even want to wrap it in a function:

function! SearchForLines(pattern1, pattern2)
    let line1 = search(a:pattern1)
    let line2 = search(a:pattern2)

    return getbufline(bufnr('%'), line1, line2)
endfunction

This way to get the list of the lines between mark 1 and mark 2 you can simply do:

:echo SearchForLines('mark 1', 'mark 2')

Edit Note that as @Christian Brabandt noted in the comments, the function getline() can also be used and in some circumstances may be easier to use. See :h getline().