29.2.4 Motion by Text Lines

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.

Command: beginning-of-line &optional count

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.

This function does not move point across a field boundary (see Fields) unless doing so would move beyond there to a different line; therefore, if count is nil or 1, and point starts at a field boundary, point does not move. To ignore field boundaries, either bind inhibit-field-text-motion to t, or use the forward-line function instead. For instance, (forward-line 0) does the same thing as (beginning-of-line), except that it ignores field boundaries.

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.

Function: line-beginning-position &optional count

Return the position that (beginning-of-line count) would move to.

Command: end-of-line &optional count

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.

This function does not move point across a field boundary (see Fields) unless doing so would move beyond there to a different line; therefore, if count is nil or 1, and point starts at a field boundary, point does not move. To ignore field boundaries, bind inhibit-field-text-motion to t.

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.

Function: line-end-position &optional count

Return the position that (end-of-line count) would move to.

Command: forward-line &optional count

This function moves point forward count lines, to the beginning of the line following that. If count is negative, it moves point −count lines backward, to the beginning of a line preceding that. If count is zero, it moves point to the beginning of the current line. If count is nil, that means 1.

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. As an explicit exception, if the last accessible line is non-empty, but has no newline (e.g., if the buffer ends without a newline), the function sets point to the end of that line, and the value returned by the function counts that line as one line successfully moved.

In an interactive call, count is the numeric prefix argument.

Function: count-lines start end

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.

Command: count-words start end

This function returns the number of words between the positions start and end in the current buffer.

This function can also be called interactively. In that case, it prints a message reporting the number of lines, words, and characters in the buffer, or in the region if the region is active.

Function: line-number-at-pos &optional pos

This function returns the line number in the current buffer corresponding to the buffer position pos. If pos is nil or omitted, the current buffer position is used.

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.