Tip 91: Replace with the Contents of a Register

Return to the top: <<Practical Vim>>

Pass by Value

• insert the contents of a register by typing <C-r>{register}

  :%s//<C-r>0/g
  

• Problems:
  • If the text in register 0 contains any characters that have special meaning within the replacement field (such as & or ~, for example), we would have to edit the string by hand to escape those characters.
  • If register 0 contained a multiline excerpt of text, it might not fit on the command line.

Pass by Reference

:%s//\=@0/g

• \=: evaluate a Vim script expression.
• @{register}: reference the contents of a register (@0 returns the contents of the yank register, while @" returns the contents of the default register.)

Comparison

Example:

:%s/Pragmatic Vim/Practical Vim/g

equivalent to:

:let @/='Pragmatic Vim'
:let @a='Practical Vim'
:%s//\=@a/g

• :let @/='Pragmatic Vim': sets the search pattern
  • equivalent to: /Pragmatic Vim <CR>
  • does not create a record in the search history
• :let @a='Practical Vim': sets the contents of the a register
  • equivalent to: visually selected the text "Practical Vim" and then typed "ay to yank the selection into register a.