Hi all,

I'm working with flex (version 2.5.4a) on GNU/linux. I used it to develop 4 scanner C files for matching different patterns within an input file. But the problem now on my hand is that I need to conditionally combine these. That is in main (placed in a separate C file other than the 4 scanner files) I'll have check the options provided by the user and accordingly call the scanner functions from the scanner C files.
For ex. if main is in file app.c and options are:
-f - for scanner function of 1st scanner file
-s - for scanner function of 2nd scanner file
-t - for scanner function of 3rd scanner file
-r - for scanner function of 4th scanner file
so something like './app -f -s -r filename' would mean that the scanners from 1st, 2nd and 4th file are called while 3rd's is not called.

The problem with such a situation is that when lex is invoked it generates C file with scanner function yylex() (and supporting functions for it). Now this function has same signature in all 4 scanners and hence the inclusion of all 4 files causes name conflict ("error: yylex() redifned here". Even -P option does not help as it just #define s the original function).

Now I hope everybody must be understanding my difficulty. Is there any way out (without changing to C++)?
While I'll like a functional decomposition as stated above but even if someone can come up with a solution where I need to combine all lex files to one and still be able to control what pattern are to be matched according to the switch provided by user in 'main()' will be a great help.

Thanks in advance!