#include <stdio.h>

void filecopy(FILE *, FILE *);

int main(int argc, char *argv[]) {
  FILE *file_p;

  if (argc == 1)
    filecopy(stdin, stdout);
  else
    while (--argc > 0)
      if ((file_p = fopen(*++argv, "r")) == NULL) {
        printf("cat: can't open: %s\n", *argv);
        return 1;
      } else {
        filecopy(file_p, stdout);
        fclose(file_p);
      }
  return 0;
}

void filecopy(FILE* in_file_p, FILE* out_file_p) {
  int ch;

  while((ch = getc(in_file_p)) != EOF)
    putc(ch, out_file_p);
}