Question

I am working in an assignment and am experiencing some weird stuff. I have this while loop in my program that does not seem to branch into the for loop. I have placed two print statements and only the “1” prints over and over again. Note that this only happens when I compile and run from the linux terminal. Now what seem weird is that if i run the exact same code (while loop plus everything else) in Netbeans it seems to compile and behave as expected. Anyone know what might be wrong. Here is the code. I appreciate your help.

while(strstr(p,string_a)!= NULL)
{
    p = trailerp + pholderp; 
    long int index =  strstr(p,string_a) - (p+1); // -1 where it hits 
    printf("1");
    for(  i = 0; i <= index; i++)
    {
        printf("2");
        p2[trailerp2] = pholderp[trailerp];
        trailerp++;
        trailerp2++;
        if(i == index)
        {  
            int j;
            for(j=0; j <= lenb-1; j++)            // insert the new string
            {
                p2[trailerp2] = string_b[j];
                trailerp2++;
            }
            trailerp++;
        }       
    }  
}    

Edit: I have found the problem. Netbeans seems to be broken in this OS.

Answer 1

This is because strstr(p,string_a) returns either p or 0 in this part:

long int index =  strstr(p,string_a) - (p+1); // -1 where it hits 

which results in index < 0 and prevents going into the loop.

You must print both p and string_a immediately before this statement to see what is going wrong there.