lex program to display line nos with string hello

 

 

 

%{
#include<stdio.h>
#include<string.h>
int ln=1;
%}
%%
“\n” {}
.*hello.* {fprintf(yyout,”\n%d:%s”,ln++,yytext);}
.* {ln++;}
%%
main()
{
yyin=fopen(“try1.txt”,”r”);
yyout=fopen(“try2.txt”,”w”);
yylex();
return 0;
}
int yywrap()
{
}

Sample output

try1.txt

hai
hello world
test file
language processor
hello

try2.txt

2:hello world
5:hello

Leave a Reply

Your email address will not be published. Required fields are marked *