Separate concerns of file reading/writing and parsing

[thierryseegers]

The function removeCode has multiple responsibilities:

1. Confirm the input FILE exists and can be read.
2. Create the output FILE for writing.
3. read/parse/write work.

I suggest modifying removeCode to accept FILE* instead and move the responsibility of file checking/creating outside of it. I think this is will facilitate unit testing.

[bouzinabdotcom]

Created FILE * open_iofile(char*, int) to fix it.

FILE * open_iofile(char * filename, int io) {
    /**
     * Function that opens input or output file depending on io parameter
     * io == 0 : reading input file
     * io == 1 : writing to output file
     * if file can't be opened: stops execution
     * else it returns a pointer on it
     * */

    FILE *f = NULL; //pointer to filename
    
    if(f = fopen(filename, (io ? "w" : "r"))) //if filename is openned for reading/writing succesfully
        return f; //return pointer
    else { //error handling for opening for reading/writing problems (ex: permissions)
        printf("Error: couldn\'t open file for %s.\n", (io ? "writing" : "reading")); 
        printf("file: %s\n", filename);

        exit(EXIT_FAILURE);
    }

    
}

Called it in the main function as follows:

removeCode(open_iofile(filename, 0), open_iofile(newfilename, 1));