Returns the x coordinates of the end of each of the characters in a string if the string was printed to a graphics port.
Returns the extents of the characters in string in the font associated with port , or the font given. The extents are an array, one element per character, which gives the ending x coordinate of that character if the string was drawn to port .
Note: To compute the extents of the entire string for a given port or font, use port-string-width or get-string-extent.
CAPI User Guide and Reference Manual (Unix version) - 3 Aug 2017