/**
 * A simple copy function for text files
 * 
 * @author gtowell
 * Created: Mar 2021
 * **/

#include <stdio.h>

#ifndef NULL
#define NULL (void *) 0
#endif

#define LINE_LEN 256

int main(int argc, char const *argv[])
{
    if (argc < 3) {
        printf("Usage: xxx existing_file_name  name_of_copy");
        return 0;
    }
    FILE *fInput = fopen(argv[1], "r");
    if (NULL == fInput)
    {
        fprintf(stderr, "Failed to open %s for reading ... terminating\n", argv[1]);
        return 1;
    }
    FILE *fOutput = fopen(argv[2], "w");
    if (NULL == fOutput)
    {
        fprintf(stderr, "Failed to open %s for output ... terminating\n", argv[2]);
        return 1;
    }

    char line[LINE_LEN];
    // this loop actually does the copying
    while (NULL != fgets(line, LINE_LEN, fInput)) {
        fprintf(fOutput, "%s", line);
    }
    // always close what was opened
    fclose(fInput);
    fclose(fOutput);
    return 0;
}