Info Catalog elisp: Text elisp: Buffer Contents

elisp: Near Point

 
 31.1 Examining Text Near Point
 ==============================
 
 Many functions are provided to look at the characters around point.
 Several simple functions are described here.  See also ‘looking-at’ in
 Regexp Search.
 
    In the following four functions, “beginning” or “end” of buffer
 refers to the beginning or end of the accessible portion.
 
  -- Function: char-after &optional position
      This function returns the character in the current buffer at (i.e.,
      immediately after) position POSITION.  If POSITION is out of range
      for this purpose, either before the beginning of the buffer, or at
      or beyond the end, then the value is ‘nil’.  The default for
      POSITION is point.
 
      In the following example, assume that the first character in the
      buffer is ‘@’:
 
           (string (char-after 1))
                ⇒ "@"
 
  -- Function: char-before &optional position
      This function returns the character in the current buffer
      immediately before position POSITION.  If POSITION is out of range
      for this purpose, either at or before the beginning of the buffer,
      or beyond the end, then the value is ‘nil’.  The default for
      POSITION is point.
 
  -- Function: following-char
      This function returns the character following point in the current
      buffer.  This is similar to ‘(char-after (point))’.  However, if
      point is at the end of the buffer, then ‘following-char’ returns 0.
 
      Remember that point is always between characters, and the cursor
      normally appears over the character following point.  Therefore,
      the character returned by ‘following-char’ is the character the
      cursor is over.
 
      In this example, point is between the ‘a’ and the ‘c’.
 
           ---------- Buffer: foo ----------
           Gentlemen may cry ``Pea★ce! Peace!,''
           but there is no peace.
           ---------- Buffer: foo ----------
 
           (string (preceding-char))
                ⇒ "a"
           (string (following-char))
                ⇒ "c"
 
  -- Function: preceding-char
      This function returns the character preceding point in the current
      buffer.  See above, under ‘following-char’, for an example.  If
      point is at the beginning of the buffer, ‘preceding-char’ returns
      0.
 
  -- Function: bobp
      This function returns ‘t’ if point is at the beginning of the
      buffer.  If narrowing is in effect, this means the beginning of the
      accessible portion of the text.  See also ‘point-min’ in 
      Point.
 
  -- Function: eobp
      This function returns ‘t’ if point is at the end of the buffer.  If
      narrowing is in effect, this means the end of accessible portion of
      the text.  See also ‘point-max’ in Point.
 
  -- Function: bolp
      This function returns ‘t’ if point is at the beginning of a line.
      Text Lines.  The beginning of the buffer (or of its
      accessible portion) always counts as the beginning of a line.
 
  -- Function: eolp
      This function returns ‘t’ if point is at the end of a line.  The
      end of the buffer (or of its accessible portion) is always
      considered the end of a line.
 

Info Catalog elisp: Text elisp: Buffer Contents