20.9 Replacement Commands

Global search-and-replace operations are not needed often in Emacs, but they are available. In addition to the simple M-x replace-string command which replaces all occurrences, there is M-% (query-replace), which presents each occurrence of the pattern and asks you whether to replace it.

The replace commands normally operate on the text from point to the end of the buffer; however, in Transient Mark mode (see Transient Mark), when the mark is active, they operate on the region. The replace commands all replace one string (or regexp) with one replacement string. It is possible to perform several replacements in parallel using the command expand-region-abbrevs (see Expanding Abbrevs).

• Unconditional Replace: Replacing all matches for a string.
• Regexp Replace: Replacing all matches for a regexp.
• Replacement and Case: How replacements preserve case of letters.
• Query Replace: How to use querying.