Thank you very much, extendad and wcs for your replies.
I read about patches and fount that really interesting. Will experiment with this next time I'll need to fix something, but I already spend about 2 hours trying to make sed work, so it's late to retreat
sed -i 's|$(bindir)|$(DESTDIR)$(bindir)|g' path/to/Makefile
Despite I have already found that / could be replaced with anything, the great thing is that your post gave me is that it pointed out about that "-i" thing!
I was wandering all the time, why my changes are shown in shell, but didn't in the file I edit. The -i option fixed that.
Also there is typo in my last post, I forgot to include fltk2-config into the second part of the script.
So, here is the script I'm using:
sed -i 's_$(bindir)/fltk2-config_$(DESTDIR)$(bindir)/fltk2-config_g' /$NAME/$VERSION/tmp/$NAME-$VERSION/fluid/Makefile
Once again, thank you for help.
It worked! Package is now ready. Will upload it to my vectorcintrib.
If you find sed handy, try Perl.
Well, that sounds even less familiar than sed for me, but thank you for reply, I think I will remember this some day