Re: [Flex-help] FW: Question regarding yyunput

[<thu...@ag...>]

Hi Aaron,

  Many many thanks for your help.  I made it works finally!  Beside =
adding=20

 void egs_unput(int c) { unput(c); }

  I also add:

 int egs_input() { input (); }=20

 You don't know how much I appreciate your suggestions and helps.  This =
is my first attempt to port something from the UX to the PC, and I had =
stucked at this point for a loooooooooong looooooooong time.  I wanted =
to port it over at the minimal effort, I did not want to rewrite the =
code (left from someone, anyway).  I alse have many more like this to =
port over.

Thanks again,
Thuyen Vu


>=20
> > Anyway, I did what you suggest and run into more problem. =20
> Here is the
> > process:
> >=20
> > -  Modified my egslex.l and egssubs.c file to replace all=20
> yyinput and
> >    yyunput to input and unput.
>=20
> Ok, I'm not sure about yyinput vs. input, but if it works that's good.
>=20
> > -  Recompiled and got the following errors:
> >=20
> > cc -O  egsarc.o egslex.o egssubs.o egs2pig.o egs_dflt.o -lm=20
> -o egs2pig
> > egssubs.o:egssubs.c:(.text+0xfb): undefined reference to `_input'
> > egssubs.o:egssubs.c:(.text+0x148): undefined reference to `_input'
> > egssubs.o:egssubs.c:(.text+0x1a6): undefined reference to `_input'
> > egssubs.o:egssubs.c:(.text+0x1e3): undefined reference to `_unput'
> > egssubs.o:egssubs.c:(.text+0x221): undefined reference to `_unput'
> > egssubs.o:egssubs.c:(.text+0x27b): undefined reference to `_input'
> > egssubs.o:egssubs.c:(.text+0x4ba): undefined reference to `_input'
> > egssubs.o:egssubs.c:(.text+0x4ec): undefined reference to `_input'
> > collect2: ld returned 1 exit status
> >=20
> > Is this because in the 'lex.yy.c' file created by the flex from my=20
> > egslex.l file, the yyunput is and yyinput are defined static?
>=20
> If you're calling those functions from outside of lex.yy.c,=20
> then yes, being static is a slight problem. The most=20
> quick-and-dirty way to handle this is to write a wrapper=20
> function inside egslex.l:
>=20
>   void egs_unput(int c) { unput(c); }
>=20
> And call egs_unput from your other source files. Typically=20
> you'd want to have the actions that are called from the lexer=20
> actions to be in the lexer file so that they have access to=20
> these static functions. But if you've set up your code some=20
> other way, wrapper functions will do the trick.
>=20
> Aaron
>=20