Question

I was requested to write a program the basically parses the file given to it, with redirecting the stdin, like this:
myProg param1 param2 param3 < theFileToParse

I’m trying to use the fopen function in order to open the given file, but i don’t understand what should i give it in the ‘const char * filename’ argument.

Answer 1

You don’t need to open the file. Your program has a special value called stdin which contains a handle to the process’s standard input stream. You can use this just as you would a file handle, for example:

int c = fgetc( stdin );

or:

fread( somebuffer, somesize, 1, stdin );