Thread: String Lifetime & Scope

Currently I am working to create a command line function that will alter data from an ini file.

The catch is to do this I will change the string in the startup array in the object defined. The code is restricted to not use C++ strings, but character arrays.

program <name>=<value>

My issue seems to be that if I want to do

program <name>=<value> <name>=<value> it will overwrite the data needed.

Code:

for( command line args)
{
  char argument[256];
  char *name;
  char *value;

  //tokenize argument into name and value

  //insert into object

}

Now even if I was to put all those variables outside the loop the issue still comes up that another pair overwrites argument.
Is there a way to make sure each argument creates new memory without having to allocate it?
or is allocating memory the only way?

btw: I also have thought about changing name and value to their own char arrays but this shouldn't make a difference because I believe my problem has to do with scope and lifetime, not the variables I am using (unless Im completely wrong)

You must copy the string into each object. If your object contains a static length character array (like your argument variable above), you can just strcpy the values on insert. If your object contains a char* variable, then before calling strcpy you must allocate space for that object's copy of the string and deallocate that space when the object is destructed.

Well the object contains a ptr to the string, so thanks for all your help.

I think I'm going to use an array to easily limit the amount of pairs that can be changed and will have to worry a little bit less about the memory mgmt (thats the only part I still am not a fan of with C/C++ compared to other languages)

Of course, you should probably not complain about the memory management required by C++ since the language provides the C++ string class for that purpose. It is not the language's fault that you code is restricted to not use the tools provided.