Next: Refinement of Difference Regions, Previous: Highlighting Difference Regions, Up: Customization

### 7.6 Narrowing

If buffers being compared are narrowed at the time of invocation of Ediff, `ediff-buffers` will preserve the narrowing range. However, if `ediff-files` is invoked on the files visited by these buffers, that would widen the buffers, since this command is defined to compare the entire files.

Calling `ediff-regions-linewise` or `ediff-windows-linewise`, or the corresponding ‘`-wordwise`’ commands, narrows the variants to the particular regions being compared. The original accessible ranges are restored when you quit Ediff. During the command, you can toggle this narrowing on and off with the `%` command.

These two variables control this narrowing behavior:

`ediff-start-narrowed`
  If `t`, Ediff narrows the display to the appropriate range when it is invoked with an ‘`ediff-regions...`’ or ‘`ediff-windows...`’ command. If `nil`, these commands do not automatically narrow, but you can still toggle narrowing on and off by typing `%`.
`ediff-quit-widened`
  Controls whether on quitting Ediff should restore the accessible range that existed before the current invocation.