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Text lines are portions of the buffer delimited by newline characters, which are regarded as part of the previous line. The first text line begins at the beginning of the buffer, and the last text line ends at the end of the buffer whether or not the last character is a newline. The division of the buffer into text lines is not affected by the width of the window, by line continuation in display, or by how tabs and control characters are displayed.
This function moves point to the front of the lineth line,
counting from line 1 at beginning of the buffer. If line is less
than 1, it moves point to the beginning of the buffer. If line is
greater than the number of lines in the buffer, it moves point to the
end of the buffer—that is, the end of the last line of the
buffer. This is the only case in which goto-line
does not
necessarily move to the beginning of a line.
If narrowing is in effect, then line still counts from the
beginning of the buffer, but point cannot go outside the accessible
portion. So goto-line
moves point to the beginning or end of the
accessible portion, if the line number specifies an inaccessible
position.
The return value of goto-line
is the difference between
line and the line number of the line to which point actually was
able to move (in the full buffer, before taking account of narrowing).
Thus, the value is positive if the scan encounters the real end of the
buffer. The value is zero if scan encounters the end of the accessible
portion but not the real end of the buffer.
In an interactive call, line is the numeric prefix argument if one has been provided. Otherwise line is read in the minibuffer.
This function moves point to the beginning of the current line. With an
argument count not nil
or 1, it moves forward
count-1 lines and then to the beginning of the line.
buffer defaults to the current buffer if omitted.
If this function reaches the end of the buffer (or of the accessible portion, if narrowing is in effect), it positions point there. No error is signaled.
This function moves point to the end of the current line. With an
argument count not nil
or 1, it moves forward
count-1 lines and then to the end of the line.
buffer defaults to the current buffer if omitted.
If this function reaches the end of the buffer (or of the accessible portion, if narrowing is in effect), it positions point there. No error is signaled.
This function moves point forward count lines, to the beginning of the line. If count is negative, it moves point -count lines backward, to the beginning of a line. If count is zero, it moves point to the beginning of the current line. buffer defaults to the current buffer if omitted.
If forward-line
encounters the beginning or end of the buffer (or
of the accessible portion) before finding that many lines, it sets point
there. No error is signaled.
forward-line
returns the difference between count and the
number of lines actually moved. If you attempt to move down five lines
from the beginning of a buffer that has only three lines, point stops at
the end of the last line, and the value will be 2.
In an interactive call, count is the numeric prefix argument.
This function returns the number of lines between the positions start and end in the current buffer. If start and end are equal, then it returns 0. Otherwise it returns at least 1, even if start and end are on the same line. This is because the text between them, considered in isolation, must contain at least one line unless it is empty.
With optional ignore-invisible-lines-flag non-nil
, lines
collapsed with selective-display are excluded from the line count.
N.B. The expression to return the current line number is not obvious:
(1+ (count-lines 1 (point-at-bol)))
Here is an example of using count-lines
:
(defun current-line () "Return the vertical position of point…" (+ (count-lines (window-start) (point)) (if (= (current-column) 0) 1 0) -1))
Also see the functions bolp
and eolp
in Near Point.
These functions do not move point, but test whether it is already at the
beginning or end of a line.
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