Книга: Learning GNU Emacs, 3rd Edition

3.2.3 Repeating Query-Replaces (and Other Complex Commands)

3.2.3 Repeating Query-Replaces (and Other Complex Commands)

Now that you've learned the basics of query-replace, let's talk about a shortcut that applies not only in query-replace but anywhere in Emacs: repeating complex commands, with slight modifications. We often exit a query-replace by mistake or decide that the replacement we really wanted was just slightly different. Do we have to type it all again? No. Simply go the beginning of the file and press C-x Esc Esc. The last complex command you typed appears. If it's not the one you want, type M-p to see the previous command (do this as many times as necessary; M-n goes to the next command). For example, let's go to the beginning of the file and repeat the query-replace we just carried out.

Type: M-< followed by C-x Esc Esc

Emacs puts the last complex command in the minibuffer; in fact it looks more complex than we remember it.

When we press M-<, we move to the beginning of the file; when we press C-x Esc Esc, the last complex command is displayed. Emacs speaks to itself in dark words, but we can still see that this is the command that we want.

This is the right command, so we don't have to press M-p to see a previous command. If we wanted to, we could change the query-replace strings before pressing Enter. In this case, the Marketing Department has once again changed the product's name from HealthBug (since bug could be construed as pest) to HealthBot (neutral, but a bit less descriptive in our opinion). Our earlier query replace changed Whirligig to HealthBug. We need to modify this command so it replaces Bug with Bot.

In the minibuffer, change Whirligig to Bug and HealthBug to Bot and press Enter.

Pressing Enter executes the command again with the modified search and replacement strings.

As we mentioned, C-x Esc Esc works for any command involving input in the minibuffer, not just query-replace. But we use this feature most frequently in query-replace. It is also good for repeating keyboard macros (see Chapter 6).

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