Vim delete blank lines

Question

What command can I run to remove blank lines in Vim?

Answer 1

This function only remove two or more blank lines, put the lines below in your vimrc, then use \d to call function

fun! DelBlank()
   let _s=@/
   let l = line(".")
   let c = col(".")
   :g/^\n\{2,}/d
   let @/=_s
   call cursor(l, c)
endfun
map <special> <leader>d :keepjumps call DelBlank()<cr>

Answer 2

:v/./d

or

:g/^$/d

or

:%!cat -s