Here are commands to get information about the size and position of parts of the buffer, and to count lines.
count-lines-region).
See section The Mark and the Region, for information about the region.
what-cursor-position).
There are two commands for working with line numbers. M-x what-line computes the current line number and displays it in the echo area. To go to a given line by number, use M-x goto-line; it prompts you for the number. These line numbers count from one at the beginning of the buffer.
M-x line-number-mode enables display of the current line number in the mode line; once you turn this on, the number updates as you move point, so it remains valid all the time. See section The Mode Line. If you narrow the buffer, only the accessible portion counts for this feature.
By contrast, M-x what-page counts pages from the beginning of the file, and counts lines within the page, printing both numbers. See section Pages.
While on this subject, we might as well mention M-= (count-lines-region),
which prints the number of lines in the region (see section The Mark and the Region).
See section Pages, for the command C-x l which counts the lines in the
current page.
The command C-x = (what-cursor-position) can be used to find out
the column that the cursor is in, and other miscellaneous information about
point. It prints a line in the echo area that looks like this:
Char: x (0170) point=65986 of 563027(12%) x=44
(In fact, this is the output produced when point is before the `x=44' in the example.)
The two values after `Char:' describe the character that follows point, first by showing it and second by giving its octal character code.
`point=' is followed by the position of point expressed as a character count. The front of the buffer counts as position 1, one character later as 2, and so on. The next, larger number is the total number of characters in the buffer. Afterward in parentheses comes the position expressed as a percentage of the total size.
`x=' is followed by the horizontal position of point, in columns from the left edge of the window.
If the buffer has been narrowed, making some of the text at the beginning and the end temporarily inaccessible, C-x = prints additional text describing the currently accessible range. For example, it might display this:
Char: x (0170) point=65986 of 563025(12%) <65102 - 68533> x=44
where the two extra numbers give the smallest and largest character position that point is allowed to assume. The characters between those two positions are the accessible ones. See section Narrowing.
If point is at the end of the buffer (or the end of the accessible part), C-x = omits any description of the character after point. The output looks like this:
point=563026 of 563025(100%) x=0