Thread: Deleting comments in another program

This program needs to delete the comments in another c program. So what I tried to do was just copy it to a new file.

Code:

#include <stdio.h>
void filecopy(FILE *, FILE *);
main()
{
   FILE *fin;
   FILE *fout;
   fin=fopen("attempt4.c","r");
   if((fout=fopen("pw.c","w"))==NULL)
    printf("GERRRRR");
   else
   filecopy(fin,fout);
   
   fclose(fin);

return 0;
}
void filecopy(FILE *ifp, FILE *ofp)
{
   int c;
   int prevc;
   while((c=getc(ifp))!=EOF)
   {
    if(prevc='/') //look for first char of a comment
       if(c='/') //find second one
       {
         while(c !='\n')
         {
        //do nothing
         }
           }
        
       else if(c='*') // find /* incase it is blocked
       {
        /*
        doesn't stop until it finds
        end of comment
        */
          while(prevc !='*' && c!='/') 
          {
        //do nothing
          }
       }
    else //copy the rest to the other file
    {
       putc(c,ofp);
       prevc=getc(ifp);
    }
   }
}

my problem is that I'm not sure how exactly to call it, I don't know if i'm doing that part right. When I run the program it doesn't do anything and I can't exit the terminal. Please help!!

It looks like you're on the right track. Some problems I see:

• You need to give prevc an initial value before the loop that isn't a slash. '\0' would be pretty safe. Otherwise it can contain anything, and while a '/' is unlikely, it's possible, and may match a comment that isn't there.
• Don't assign prevc the value from getc(ifp). That makes it the next character. You want to assign it the value of c. Also, don't do it in the else block, do it as the last statement in the loop, regardless of whether you're in a comment.
• You need to check both file pointers for NULL after you open them. If either one is NULL, you can't open the file, so you need to close any open ones, print an error and quit.

There are also issues with the use of the assignment equals (=) used where the comparison equals (==) should be used .

if(prevc='/') //look for first char of a comment
if(c='/') //find second one