/*
 * Program to mimic "cat" command:
 *
 * With no command-line arguments, echoes text from stdin to stdout.
 * 
 * With one or more command-line arguments representing filenames,
 * copies files to stdout.
 */
#include <stdio.h>

void copy_file(FILE * infile, FILE * outfile);

int main(int argc, char *argv[]) {
	if (argc == 1) {
		copy_file(stdin, stdout);
		return 0;
	}
	else {
		int rval = 0;
		for (int i = 1; i < argc; ++i) {
			FILE * instream = fopen(argv[i], "r");
			if (instream == NULL) { 
				fprintf(stderr, "cannot open file %s\n", argv[i]);
				rval = 1;
			}
			else {
				copy_file(instream, stdout);
				fclose(instream);
			}
		}
		return rval;
	}
}

void copy_file(FILE * infile, FILE * outfile) {
	int ch;
	int count = 0;
	while ((ch = fgetc(infile)) != EOF) {
		fputc(ch, outfile);
		count += 1;
	}
}