> Date: Mon, 26 Dec 2016 22:24:21 +0000 (GMT) > From: Jan Wedekind <j...@wedesoft.de> > Cc: guile-user@gnu.org > > I think "libc" is normally loaded already. E.g. the C function "abs" can > be accessed as follows: > > (define main (dynamic-link)) > (define cabs (pointer->procedure long (dynamic-func "abs" main) (list > long))) > (cabs -42) > ; 42
This is non-portable, and doesn't work outside of the Posix world. E.g., on MS-Windows (with Guile 2.0.x): D:\usr\eli\data>guile GNU Guile 2.0.11 Copyright (C) 1995-2014 Free Software Foundation, Inc. Guile comes with ABSOLUTELY NO WARRANTY; for details type `,show w'. This program is free software, and you are welcome to redistribute it under certain conditions; type `,show c' for details. Enter `,help' for help. scheme@(guile-user)> ,use (system foreign) scheme@(guile-user)> ,use (rnrs bytevectors) scheme@(guile-user)> (define main (dynamic-link)) scheme@(guile-user)> (define cabs (pointer->procedure long (dynamic-func "abs" main) (list long))) ERROR: In procedure dynamic-func: ERROR: In procedure dynamic-pointer: Symbol not found: abs Entering a new prompt. Type `,bt' for a backtrace or `,q' to continue. scheme@(guile-user) [1]> ,q But (msvcrt.dll is the C runtime library on Windows): scheme@(guile-user)> (define libc (dynamic-link "msvcrt.dll")) scheme@(guile-user)> (define cabs (pointer->procedure long (dynamic-func "abs" libc) (list long))) scheme@(guile-user)> (cabs -42) $1 = 42 scheme@(guile-user)>
