Compilation principle course assignments, not really, to help
Need to use flex to HTML file into a TXT file
Requirement is:
(1) remove all HTML tags, HTML and the converted file directly output to the screen.
(2) to delete all the start tag for & lt; Script...> , & lt; Style...> And & lt; The form...>
End tag for & lt;/script> , & lt;/style> And & lt;/form> Among all the content
(3) all the anchor of the hyperlink, and save it in a new text file hyplink. TXT in

/* like NONEED SCPT and the FORM, please complete the TAG, the LINK condition mode corresponds to the
Regular expressions, and the corresponding action */C

Html2txt. L as follows:

 % {
#include  
#include  
The FILE * hyplink; 
Int lastchar;/* if the last output char is newline */
%} 
NONEED % x 
% x FORM 
% x LINK 
% x SCPT 
% x TAG 
The COMMENT % x 
% % 
(" & lt;" [sS] [cC] [rR] [iI] [pP] [tT] [^ & gt;] * & gt; "" ) the BEGIN (SCPT); 
(" & lt;" [sS] [tT] [yY] [lL] [eE] [^ & gt;] * & gt; "" ) the BEGIN (NONEED); 
"& lt;" [iI] [fF] [rR] [aA] [mM] [eE] [^ & gt;] * & gt; "" The BEGIN (NONEED); 
(" & lt; ! "[sS] [cC] [rR] [iI] [pP] [tT] [^ & gt;] * & gt; "" ) the BEGIN (SCPT); 
(" & lt;" [Ff] [oO] [rR] [Mm] [^ & gt;] * & gt; "" ) the BEGIN (FORM); 

"& lt;" (aA) BEGIN (LINK); 
"& lt;" The BEGIN (TAG); 

" " <"[iI]/[fF] [rR] [aA] [mM] [eE] [^ & gt;] * & gt; "" The BEGIN (INITIAL); 
 . | \ n; 


"/"[sS] [cC] [rR] [iI] [pP] [tT] [^ & gt;] * & gt; "" + (\ n) * the BEGIN (INITIAL); 
 . | \ n {; } 

 (" & lt;/"[Ff] [oO] [rR] [Mm] [^ & gt;] * & gt; "" + (\ n) *) the BEGIN (INITIAL); 
 . | \ n {; 

/* like NONEED SCPT and the FORM, please complete the TAG, the LINK condition mode corresponds to the 
Regular expressions, and the corresponding action */C 
} 
(& amp; [qQ] [oO] [tT] ";" ) {
Printf (" '"); 
} 
(& amp; [they] [tT] ";" ) {
Printf (" & gt;" ); 
} 
(& amp; [lL] [tT] ";" ) {
Printf (" & lt;" ); 
} 
(& amp; [aA] [mM] [pP] ";" ) {
Printf (" & amp;" ); 
} 
(& amp; [nN] [bB] [sS] [pP] ";" ) {
Printf (" "); 
} 

[\ r \ t] * {; } 
(" & lt;/[lL] [iI] "" & gt;" ) {; } 
(" & lt;/[pP] "" & gt;" ) {; } 
(" -- & gt;" ) {; } 




% % 

Int main (int arg c, char * * argv) 
{
+ + argv - arg c; 
If (arg c & gt; 0 {
If ((yyin=fopen (argv [0], "rb"))==NULL) {
Printf (" the file % s could 'nt open! \ n ", argv [0]); 
exit (1); 
} 
} 
The else 
Yyin=stdin; 
If ((hyplink=fopen (" hyplink. TXT ", "w"))==NULL) {
Printf (" coud 'nt create the hyperlink to the file! \n"); 
exit(1); 
} 
Yylex (); 
The fclose (yyin); 
The fclose (hyplink); 
return 0; 
} 

Int yywrap () 
{
return 1; 
}