LEX program to add line numbers to a given file
EXAMPLE :-
Create first file line.l or line.lex , and Create Second file line.java
line.l
%{
int line_number = 1;
%}
line .*\n
%%
{line} { printf("%10d %s", line_number++, yytext); }
%%
int yywrap(){}
int main(int argc, char*argv[])
{
extern FILE *yyin;
yyin = fopen("line.java","r");
yylex();
return 0;
}
INPUT :-
line.java
class hello{
public static void main(String args[]){
System.out.println("Hello World !");
}
}
OUTPUT
sunny@sunny-PC:~/Desktop$ flex line.l
sunny@sunny-PC:~/Desktop$ gcc lex.yy.c
sunny@sunny-PC:~/Desktop$ ./a.out
1 class hello
2 {
3 public static void main(String args[])
4 {
5 System.out.println("Hello World !");
6 }
7 }
