Within some text files, text is divided into pages delimited by the formfeed character (ASCII code 12, also denoted as <control-L>), which is displayed in Emacs as the escape sequence ‘^L’ (see Text Display). Traditionally, when such text files are printed to hardcopy, each formfeed character forces a page break. Most Emacs commands treat it just like any other character, so you can insert it with C-q C-l, delete it with <DEL>, etc. In addition, Emacs provides commands to move over pages and operate on them.
M-x what-page counts pages from the beginning of the file, and counts lines within the page, showing both numbers in the echo area.
The C-x [ (
backward-page) command moves point to immediately
after the previous page delimiter. If point is already right after a page
delimiter, it skips that one and stops at the previous one. A numeric
argument serves as a repeat count. The C-x ] (
command moves forward past the next page delimiter.
The C-x C-p command (
mark-page) puts point at the
beginning of the current page (after that page delimiter at the
front), and the mark at the end of the page (after the page delimiter
at the end).
C-x C-p C-w is a handy way to kill a page to move it elsewhere. If you move to another page delimiter with C-x [ and C-x ], then yank the killed page, all the pages will be properly delimited once again. The reason C-x C-p includes only the following page delimiter in the region is to ensure that.
A numeric argument to C-x C-p specifies which page to go to, relative to the current one. Zero means the current page, one the next page, and −1 the previous one.
The C-x l command (
count-lines-page) is good for deciding
where to break a page in two. It displays in the echo area the total number
of lines in the current page, and then divides it up into those preceding
the current line and those following, as in
Page has 96 (72+25) lines
Notice that the sum is off by one; this is correct if point is not at the beginning of a line.
page-delimiter controls where pages begin. Its
value is a regular expression that matches the beginning of a line
that separates pages (see Regexps). The normal value of this
"^\f", which matches a formfeed character at the
beginning of a line.