CS256 - Fundamentals of Structured Programming

Displaying exercises/e9/solution/f3.c

#include <stdio.h>

/**
 * Make the program take two filenames on the command line.  Print the usage
 * message "f3 <filename> <filename>\n" if not enough command line parameters
 * are provided.
 * Open the first filename for reading and the second filename for writing.
 * Copy the contents of the first file into the second file.  It would
 * probably be easiest to do this one character at a time, using fgetc and
 * fputc.
 */
int main(int argc, char *argv[])
{

  if (argc < 3) {
    printf("f3 <filename> <filename>\n");
    return 1;
  }

  FILE *in = fopen(argv[1], "r");
  if (in == NULL) {
    printf("Error opening input file.\n");
    return 1;
  }
  
  FILE *out = fopen(argv[2], "w");
  if (in == NULL) {
    printf("Error opening output file.\n");
    return 1;
  }

  int ch;
  
  while((ch = fgetc(in)) != EOF) {
    fputc(ch, out);
  }
  fclose(in);
  fclose(out);
  
  return 0;
}