[ns] FILE * producing segmentation fault

[Meeta Gupta]

hi users,
 
                 please help me with this problem. i am trying to implement a 
new agent. i have a method that is periodically invoked to write some 
statistics in a file. whenever i try to print something in the text file using 
fprintf i get a segmentation fault. anything without the file pointer seems to 
work. i have the following lines in my c++ code....
 
void myAgent:: print_info()
{
       FILE * fp;
       fp = fopen("/Documents/ns-allinone-2.31/text.txt", "a");
  
 
}