Detect different tokens in a C program | Compiler Design

Each C program consists of various tokens. A token can be either a keyword, an identifier, a constant, a string literal, or a symbol. We use Lexical Analysis to convert the input program into a sequence of tokens and for detection of different tokens.

Code

/* Decalring two counters one for number
of lines other for number of characters */
%{
int keywordCount = 0;
int identifiersCount = 0;
int specialCharCount = 0;
int constantsCount = 0;
int punctuationCount = 0;
%}

/**rule 1 counts the number of lines, rule 2 counts the number of characters and rule 3 specifies when to stop taking input **/
%%
end return 0;
bool|int|float printf("Keyword\n"); keywordCount++;
[-,+]?[0-9]+ printf("Constants\n"); constantsCount++;
[,.'", ;]+ printf("Punctuation Chars\n"); punctuationCount++;
[!@#$%^&*(){}=]+ printf("Special Chars\n"); specialCharCount++;
[_,a-zA-Z]+ printf("Identifiers\n"); identifiersCount++;
%%

/* User code section***/
int yywrap(){}
int main(int argc, char **argv)
{
       yylex();
       printf("Keywords: %d\nConstants: %d\nPunctuations: %d\nSpecial characters %d\nIdentifiers: %d\n", keywordCount, constantsCount, punctuationCount, specialCharCount, identifiersCount);
       return 0;
}

Output

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