file.l

lex files for given decription used as assignment in compiler design

%{
#include<stdio.h>

%}

%%


auto |
break |
case |
char |
const |
continue |
default |
do |
double |
else |
enum |
extern |
float |
for |
goto |
if |
int |
long |
register |
return |
short |
signed |
sizeof |
static |
struct |
switch |
typedef |
union |
unsigned |
void |
volatile |
while { printf("%s :keyword\n",yytext);}
[0-9]+ {printf("%s: integer",yytext);}
[0-9]*[.][0-9]+ { printf("%s : floating point number\n",yytext);}
[0-9]*[.] { printf("%s: invalid input\n",yytext);}




['][a-zA-Z0-9]['] { printf("%s : character constant\n",yytext);}

["][a-zA-Z0-9 ,./?=+-]*["] { printf("%s : string\n",yytext);}


[/][/][A-Za-z0-9;, *#$%&!@()]*[\n]  { printf("%s : comment line\n",yytext);}
[/][*][A-Za-z0-9;, *#$%&!@()\n]*[*][/] { printf("%s : comment line\n",yytext);}

[#][A-Za-z0-9<. ]*[>] { printf("%s : Header file\n",yytext);}


[=] |
[+][+] |
[-][-] |
[=][=] |
[/] |
[+] |
[-] |
[*] |
[?] |
[%] |
[!] |
[!][=] |
[<] |
[>] |
[<][=] |
[>][=] |
[&] |
[&][&] |
[|][|] { printf("%s : operator\n",yytext);}

[a-zA-Z]+[0-9]* { printf("%s : identifier\n",yytext);}

[(] { printf("%s : left parenthesis\n",yytext);}
[)] { printf("%s : right parenthesis\n",yytext);}

[{] { printf("%s : left brace\n",yytext);}
[}] { printf("%s : right brace\n",yytext);}
[;] { printf("%s : semi-colon\n",yytext);}
[,] { printf("%s : comma\n",yytext);}
[[] { printf("%s : left array index\n",yytext);}
[]] { printf("%s : right array index\n",yytext);}


%%

main()
{
       yylex();
}