cp_files.c

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <dirent.h>
#include <errno.h>
#include <string.h>

int
main(int argc, char *argv[])
{
	int tfd;
	DIR *sdir;
	struct dirent *dirent;

	if (argc != 3) {
		fprintf(stderr, "Usage: %s SRC DST\n", argv[0]);
		exit(1);
	}

	sdir = opendir(argv[1]);
	if (sdir == NULL) {
		fprintf(stderr, "Failed to open %s: %s\n",
		    argv[1], strerror(errno));
		exit(2);
	}

	tfd = open(argv[2], O_DIRECTORY);
	if (tfd < 0) {
		fprintf(stderr, "Failed to open %s: %s\n",
		    argv[2], strerror(errno));
		closedir(sdir);
		exit(3);
	}

	while ((dirent = readdir(sdir)) != NULL) {
		if (dirent->d_name[0] == '.' &&
		    (dirent->d_name[1] == '.' || dirent->d_name[1] == '\0'))
			continue;

		int fd = openat(tfd, dirent->d_name, O_CREAT|O_WRONLY, 0666);
		if (fd < 0) {
			fprintf(stderr, "Failed to create %s/%s: %s\n",
			    argv[2], dirent->d_name, strerror(errno));
			closedir(sdir);
			close(tfd);
			exit(4);
		}
		close(fd);
	}

	closedir(sdir);
	close(tfd);

	return (0);
}