Lex Program to accept string starting with vowel
Lex is a computer program that generates lexical analyzers. Lex reads an input stream specifying the lexical analyzer and outputs source code implementing the lexer in the C programming language.
The commands for executing the lex program are:
lex abc.l (abc is the file name) cc lex.yy.c -efl ./a.out
Let’s see lex program to accept string starting with vowel.
Examples:
Input: animal Output: Accepted Input: zebra Output: Not Accepted
Below is the implementation:
/* Lex Program to accept string starting with vowel */% { int flag = 0;% } %% [aeiouAEIOU].[a-zA-Z0-9.]+ flag=1;[a-zA-Z0-9]+ %% main(){ yylex(); if (flag == 1) printf("Accepted"); else printf("Not Accepted"); } |
Output:
