A READ-LINE alternative that handles MS/Mac/Unix end-of-line conventions.
The Common Lisp read-line function only looks for linefeed characters as
the basis of line termination. In Common Lisp's defense, linefeeds were an
entirely adequate convention for text line termination, Microsoft hadn't
been around long enough to screw everything up, and Apple wasn't even a gleam in
anybody's eye. Ah well, progress, or failing that, some printer did the
right thing with the right EOL conventions in some context at some time.
This module provides a function, read-line-crlf, which treats any of the
following sequences as a single line separation.
LF, CR, CRLF
In particular, CRLF indicates ONE logical end-of-line.
Have a nice day.
If you didn't get this via quicklisp from the quicklisp repo (because it isn't
there yet), add it to your ~/quicklisp/localprojects/ directory, update/wipe
the system-index.txt file accordingly, and then you can quickload it.
;; See 'local-projects' note in preceding paragraph
(ql:quickload :read-line-crlf) ; to use the code
And from there you can import/use the exported read-line-crlf
function anywhere you would otherwise use read-line.
To run tests:
;; (again, see 'local-projects' note if applicable)
(ql:quickload :read-line-crlf-test)
(read-line-crlf-test:run-tests)
read-line-crlf takes an optional buffer parameter after all the standard
READ-LINE parameters. If you're calling it
in a loop you can avoid some consing by passing a larger buffer, e.g.
(let ((buffer (make-string 1024)))
(loop ...
(read-line-crlf stream nil nil nil buffer) ...))
SBCL, CCL, ABCL, Allegro CL, ECL were tested and working fine with relatively recent releases as of Feb 10 2024.
LispWorks 8 works as well, but I'm unsure how to declare the buffer for
optimal effect (not that I've done that correctly for other lisps, but at
least they don't break), so the buffer type declaration is omitted for LispWorks.
See read-line-crlf function code for more details.