In C how do I print filename of file that is redirected as input in shell

Question

$cc a.c
$./a.out < inpfilename

I want to print inpfilename on stdout. How do I do that ? Thanks for the help in advance...

Answer 1

As you put it the process that runs a.out has no notion of the file name of the file that provides its' standard input.

The invocation should be:

$ ./a.out inputfilename

and parse argv in int main( int argc, char* argv[] ) { ... }

or

$ ./a.out <<< "inputfilename"

And get the filename from stdin.

Then in a.c you need to fopen that file to read it's content.