[Spf-dev] Calling unix shell from SP-Forth

[Eduardo C. <edu...@ya...>]

In a previous article, I asked how to call system services from SP-Forth. Of course, it is easy to call libc and other dynamic libraries from SP-Forth.

~/frt/fpForth$ rlwrap ./spf.nux
SP-FORTH - ANS FORTH 94 for Linux
Open source project at http://spf.sf.net
Russian FIG at http://www.forth.org.ru ; Started by A.Cherezov
Version 4.20 Build 001 at 24.Feb.2013

(( S" ls *.f" )) system DROP
ansi-block.f  fsm.f        martinBrad.f  sbnf.f      xconsole.f
bernd.f       gram.f        mbrad.f       sexp.f      xeca.f
brad.f          grammar.f        mulmat.f      strings.f   zeca.f
 Ok

However, if I call cd (change directory), SP-Forth seems to ignore my command.


(( S" cd $HOME" )) system DROP
 Ok
(( S" pwd" )) system DROP
/home/rosa/frt/fpForth
 Ok

As you can see, the command S" cd $HOME" was ignored. I believe that system creates a new shell, changes the directory in the new shell, and reverts to the old shell when control is returned to SP-Forth. My question is: How to inhibit this behavior? Since I want to create a shell language piggybacked on SP-Forth, I need a persistent cd command.