Write a program to check a C program for rudimentary syntax errors like unbalanced parentheses, brackets, and braces. Don’t forget about quotes, both single and double, escape sequences, and comments.(This program is hard if you do it in full generality.)

#include <stdio.h>

int brace, brack, paren;

void in_quote(int c);
void in_comment(void);
void search(int c);

/*rudimentary syntax checker for C programs     */
int main(){
    int c;
    extern int brace, brack, paren;

    while ((c =getchar()) != EOF) {
         if(c =='/'){
             if ((c =getchar()) == '*')
                    in_comment();    /*inside comment */
             else
                  search(c);
         }else if (c =='\' || c ==' " ')
               in_quote(c);    /* inside quote */
         else
              search(c);
        if (brace < 0){   /* output errors */
            printf("Unbalanced braces \n");
            brace = 0;
        }else if (brack < 0){
              printf("Unbalanced brackets \n");
              brack = 0;
        }else if ( paren < 0) {
               printf("Unbalanced parentheses\n");
               paren = 0;
        }
        if (brace > 0)   /*output errors */
              printf("Unbalanced braces\n");
        if (brack > 0)
             printf("Unbalanced brackets\n");
        if (paren > 0)
            printf("Unbalanced parentheses\n"); 
    }
   /* search: search for rudimentary syntax errors    */
   void search(int c) {
        extern int brace, brack, paren;
      if (c == '{')
           ++brace;
      else if (c ==' }')
           --brace;
       else if (c == '[')
           ++brack;
       else if (c == ']')
           --brack;
       else if (c == '(')
            ++paren;
       else if (c == ')')
            --paren;
   }
  /* in_comment: inside of a valid comment     */
 void in_comment(void){
      int c, d;
       c = getchar();    /*prev character */
       d = getchar();    /* curr character */
       while (c != '*' || d != '/'){   /* search for end */
           c = d;
           d = getchar();
       }
}

/*in_quote: inside quote              */
void in_quote(int c){
     int d;

     while((d =getchar()) != c)   /* search end quote  */
         if ( d == '\\')
               getchar();    /* ignore escape seq;
}
}