/*
    fileio.c
	Jeff Ondich, 26 April 2019
    Part of a quick intro to C
*/
#include <stdio.h>
#include <ctype.h>

int main(int argc, char *argv[]) {
    // Check the command-line syntax and offer a usage statement
    // if it's not OK. It's conventional to return 1 to indicate
    // to the shell/terminal that an error occurred while running
    // this program.
    if (argc != 3) {
        fprintf(stderr, "Usage: %s inputFileName outputFileName\n", argv[0]);
        return 1;
    }

    // OK, we have file names. Let's try opening them for reading (inputFile)
    // and writing (outputFile).
    FILE *inputFile = fopen(argv[1], "r");
    if (inputFile == NULL) {
        fprintf(stderr, "We could not open the file %s for reading.\n", argv[1]);
        return 1;
    }

    FILE *outputFile = fopen(argv[2], "w");
    if (outputFile == NULL) {
        fprintf(stderr, "We could not open the file %s for writing.\n", argv[2]);
        return 1;
    }

    // Yipee, our files are ready to go! Read one character at a time out of
    // the input file and write it in upper case to the output file.
    char ch;
    while ((ch = fgetc(inputFile)) != EOF) {
        fputc(toupper(ch), outputFile);
    }

    // Be nice and clean up after yourself.
    fclose(inputFile);
    fclose(outputFile);

    return 0;
}