Searching and replacing in emacs


Day two of my serie about emacs, about searching and replacing.

  • Function name: isearch-forward
  • Typical Key binding: C-s
  • How to get help: C-h f isearch-forward

isearch-forward let you type a string to be searched incrementally in the current buffer, successive following C-s will jump to the next match.

  • Function name: isearch-forward-regexp
  • Typical Key sequence: C-M-s or C-u C-s
  • How to get help : C-h f isearch-forward-regexp

isearch-forward-regexp let you type a regexp to be searched incrementally in the current buffer, successive following C-s will jump to the next match.

  • Function name: query-replace
  • Typical key binding: M-%
  • How to get help: C-h f query-replace
  • Usage: M-% search RET replace RET

Then, for each term found, query-replace will ask you what to do: space or y to replace, delete or n to skip, RET or q to exit, ! for "yes for all", ? to get help about how to enter recursive edit / delete match and recursive edit / edit replacement string / ... Then you should read about replace-string, replace-regexp, occur, list-matching-lines, multi-occur, multi-occur-in-matching-buffers, how-many, flush-lines, and keep-lines.

Case sensitivity: A search is by defaut case insensitive, but if you input an upper case letter, it become case sensitive. M-c during a search toggle the case sensitivity. Configuration variables: You may consult the documentation about those variable typing : C-h v *variable* or M-x apropos-variable RET case-fold-search RET

  • case-fold-search (Non-nil if searches and matches should ignore case.)
  • default-case-fold-search (Default value of `case-fold-search')
  • tags-case-fold-search (Whether tags operations should be case-sensitive.)