C main parameter

Question

I wrote a code which has to display main parameters, but when I compiled it and typed in "*" program shows my file structure. Command in cmd looks like this: program.exe 1 2 3 *

#include <stdio.h>
#include <stdlib.h>

int main(int argc, char const* argv[]) {
    for (int i=0; i<argc; i++) printf("%s\n", argv[i]);
    return 0;
}

The result is:

program
1
2
3
program.c
program.exe
10-03-20
11-02-20

And my question: Is it possible to force program to print "*" instead of listing files.

Answer 1

mingw causes the program to perform wildcard expansion of the parameters. Add the following to your program to disable this behaviour:

int _CRT_glob = 0;

---

In the unix world, the shell is expected to perform wildcard expansion.

$ perl -le'print for @ARGV' *
a
b

In the Windows world, wildcard expansion is left to the application.

>perl -le"print for @ARGV" *
*

That makes writing portable programs tricky. Since mingw is often used to compile programs that weren't written with Windows in mind, its C runtime library performs wildcard expansion of the parameters automatically.

a.c:

#include <stdio.h>

int main(int argc, char const* argv[]) {
    for (int i=0; i<argc; i++)
        printf("%s\n", argv[i]);

    return 0;
}

>gcc -Wall -Wextra -pedantic-errors a.c -o a.exe & a *
a
a.c
a.exe

But, mingw provides an out. Adding the following to your program disables this behaviour:

int _CRT_glob = 0; 

a.c:

#include <stdio.h>

int _CRT_glob = 0; 

int main(int argc, char const* argv[]) {
    for (int i=0; i<argc; i++)
        printf("%s\n", argv[i]);

    return 0;
}

>gcc -Wall -Wextra -pedantic-errors a.c -o a.exe & a *
a
*