I'm studying C in order to start doing some fun low-level code stuff, and I've stumbled into a scenario which I can't wrap my head around, and I'm sure it's because I don't have a lot of experience with it.
Currently my code is very simple: it takes some arguments, and gets the first parameter passed to main, and stores it as a path string. The first question that came to mind, was whether it would be correct to store the main params as char *args[] or char **args, and I decided to go with char **args since according to this question there could be some scenarios where the first would not be accessible, and I just wanted to make a code that would be as complete as possible, and learn the whys on the process.
Here's is the code:
int main(int argc, char **args) {
if (args[1] == NULL) return 1;
// Get path of input file
char *path = &*args[1];
fputs(path, stdout);
return 0;
}
Given the code above, what would be a better way of fetching the value stored in *args[1]? It seems very cryptic when I look at it, and it took me a while to get to it as well.
My understanding is that char **args, is a pointer, to an array of pointers. Thus, if I'm to store a string or any other value for later use in one of the indexes of args, I would have to assign a new pointer to a memory location (*path), and assign the value of the given index to it (&*args[i]). Am I over complicating things? Or is this thought process correct?
For starters these two function declarations
int main(int argc, char **args)
and
int main(int argc, char *args[])
are fully equivalent because the compiler adjusts the parameter that has an array type to pointer to the array element type.
In the initializer expression of this declaration
char *path = &*args[1];
applying the two operators & and * sequentially is redundant. So you may just write
char *path = args[1];
Also in general instead of the condition in the if statement
if ( args[1] == NULL) return 1;
it will be more safer to write
if ( argc < 2 ) return 1;