#include <stdio.h>
#include <stdlib.h>

void filecopy(FILE *, FILE *);

int main(int argc, char *argv[]) {
  FILE *file_p;
  char *prog_name = argv[0];

  if (argc == 1)
    filecopy(stdin, stdout);
  else
    while (--argc > 0)
      if ((file_p = fopen(*++argv, "r")) == NULL) {
        fprintf(stderr, "%s: can't open: %s\n", prog_name, *argv);
        exit(1);
      } else {
        filecopy(file_p, stdout);
        fclose(file_p);
      }
  if (ferror(stdout)) {
    fprintf(stderr, "%s: error writing stdout\n", prog_name);
    exit(2);
  }
  exit(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);
}