Whenever flex can not match the input it says "flex scanner jammed".

You need to add a rule that matches the otherwise-unmatched text. e.g.,

%option yylineno
%%
[[a bunch of rules here]]

.	printf("bad input character '%s' at line %d\n", yytext, yylineno);

See %option default for more information.

This document was generated by Wolfram Kahl on September, 9 2006 using texi2html 1.76.