Menu
What numbers of arguments are used for main? What variants of main definition is possible?
851
Yes, we can give arguments in the main() function. Command line arguments in C are specified after the name of the program in the system's command line, and these argument values are passed on to your program during program execution. The argc and argv are the two arguments that can pass to main function.
There are at least two arguments to main : argc and argv . The first of these is a count of the arguments supplied to the program and the second is an array of pointers to the strings which are those arguments—its type is (almost) 'array of pointer to char '.
There are two parameters passed to main(). The first parameter is the number of items on the command line (int argc). Each argument on the command line is separated by one or more spaces, and the operating system places each argument directly into its own null-terminated string.
Every C program has a primary (main) function that must be named main. If your code adheres to the Unicode programming model, you can use the wide-character version of main, wmain. The main function serves as the starting point for program execution.
C++ Standard: (Source)
The C++98 standard says in section 3.6.1.2
It shall have a return type of type int, but otherwise its type is implementation-defined. All implementations shall allow both the following definitions of main: int main() and int main(int argc, char* argv[])
Commonly there are 3 sets of parameters:
void
int argc, char ** argvint argc, char ** argv, char ** env Where argc is the number of command lines, argv are the actual command lines, and env are the environment variables.
Windows:
For a windows application you have an entry point of WinMain with a different signature instead of main.
int WINAPI WinMain(
__in HINSTANCE hInstance,
__in HINSTANCE hPrevInstance,
__in LPSTR lpCmdLine,
__in int nCmdShow
);
OS X: (Source)
Mac OS X and Darwin have a fourth parameter containing arbitrary OS-supplied information, such as the path to the executing binary:
int main(int argc, char **argv, char **envp, char **apple)
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
