You're mixing things up here.
First of all, fgets() is a C function (included via the header cstdio). You are reading from a file into a C-style array, then creating a C++ string from the line you read. This is pointless. C++ includes functionality for reading lines from files as well, without the limitation of reading to a fixed-length buffer:
#include <fstream>
#include <string>
std::vector<std::string> sLines;
std::ifstream infile("testfile.txt");
while(!infile.eof())
{
std::string s;
std::getline(infile, s);
sLines.push_back(s);
}
infile.close();
getline() will read a string until a newline is encountered, without the maximum size limit of 255 that the fixed-length C-style read has. The allocation is invisibly handled by the string class.
And no, you don't need to free sLines explicitly; it will be freed when it goes out of scope. The only things you need to free are things you explicitly new. That's the beauty of using C++ standard library functionality, rather than C or (as you are doing here) a bastard mix of C and C++.
Now, I take it from the second part of your code that you need sProgram to be an array of pointers to C-style strings (for whatever reason). Rather than explicitly using new/delete you could do something like this (note that this is still somewhat C-ish, and there are other and more concise ways of doing it in straight C++; but now is not the time to introduce lambdas, I think ;) ):
std::vector<const char *> sProgram;
for(unsigned int i=0; i<sLines.size(); ++i)
{
sProgram.push_back(sLines.c_str());
}
If you have C++11 you can then call sProgram.data() to get a pointer to the array of const char * held by sProgram, and use that wherever you are using your current sProgram pointer. If you don't have C++11, then the line &sProgram[0] works, though it is, of course, a bit hacky, (and the pointer is invalidated if you do another push_back that causes a reallocation, so be careful). This way, sProgram is also automatically managed (it grows as needed when more lines are added, and is automatically deleted when it goes out of scope) without the explicit new/delete calls. Even better would be to re-work whatever it is you need sProgram for so it doesn't require an array of C-style strings, but this might not always be possible if you are sending it to a third party library or API (such as a shader compiler, which I suspect you are doing).
In this day and age, if you are using a C++ compiler and you are doing explicit allocating/de-allocating of arrays and strings, then you really ought to take a good hard look at what you are doing and why, as there are almost always safer ways to do it that don't require possibly unsafe memory management.
