Compiler Design Lap Program :
%{
#include<stdio.h>
int id=0;
%}
%%
[a-zA-Z][a-zA-Z0-9_]* { id++ ; ECHO; printf(“\n”);}
.+ { ;}
\n { ;}
%%
int yywrap()
{
return 1;
}
main (int argc, char *argv[])
{
if(argc!=2)
{
printf(“Usage: <./a.out> <sourcefile>\n”);
exit(0);
}
yyin=fopen(argv[1],”r”);
printf(“Valid identifires are\n”);
yylex();
printf(“No of identifiers = %d\n”,id);
}