Question

I have an interesting problem.

I define,

typedef char *string;

char array[10];    
string buf[10];  
i=0;  
while(1){    
  array=<assign_string>       
  buf[i]= array;        
  i++;
}    

At each iteration i assign different strings. For instance,
buf[0] should be “1111111111”
buf[1] should be “2222222222” and so on.
However when i assign “2222222222” when i=1, buf[0] also changes to “2222222222”. What could be the problem?

Answer 1

The problem is that all entries in buf point to the same string – the one named array. So changing array will affect all buf entries.

You could fix this by allocating a new string for every iteration, e.g. your pseudo-code would become:

string buf[10];  
i=0;  
while(1){    
  buf[i]= strdup( <array_string> );
  i++;
}

Make sure to free() all the strings when you’re done using them.