From: Richard M. Stallman Date: Thu, 9 Jul 1998 04:03:27 +0000 (+0000) Subject: Explain "prefix arg". Explain how it can be a flag. X-Git-Tag: emacs-20.3~357 X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=973cefd24a2e4c70400ebc0a75257d086d333906;p=emacs.git Explain "prefix arg". Explain how it can be a flag. --- diff --git a/etc/TUTORIAL b/etc/TUTORIAL index 65020a8df97..2acaf41dc21 100644 --- a/etc/TUTORIAL +++ b/etc/TUTORIAL @@ -191,18 +191,23 @@ is by typing C-u and then the digits before you type the command. If you have a META (or EDIT or ALT) key, there is another alternative way to enter a numeric argument: type the digits while holding down the META key. We recommend learning the C-u method because it works on -any terminal. +any terminal. The numeric argument is also called a "prefix argument", +because you type the argument before the command it applies to. For instance, C-u 8 C-f moves forward eight characters. >> Try using C-n or C-p with a numeric argument, to move the cursor to a line near this one with just one command. -Most commands use the numeric argument as a repeat count. Certain -exceptional commands use it differently. C-v and M-v are among the -exceptions. When given an argument, they scroll the screen up or down -by that many lines, rather than by a screenfuls. For example, C-u 4 -C-v scrolls the screen by 4 lines. +Most commands use the numeric argument as a repeat count, but some +commands use it in some other way. Several commands (but none of +those you have learned so far) use it as a flag--the presence of a +prefix argument, regardless of its value, makes the command do +something different. + +C-v and M-v are another kind of exception. When given an argument, +they scroll the screen up or down by that many lines, rather than by a +screenful. For example, C-u 8 C-v scrolls the screen by 8 lines. >> Try typing C-u 8 C-v now.