#include <stdio.h>

#include <errno.h>
#include <error.h>
#include <fcntl.h>
#include <sysexits.h>
#include <unistd.h>

int main(int argc, char *argv[]) {
	if (argc < 2) {
		printf("usage: %s <file> [...]\n", argc > 0 ? *argv : "dontneed");
		return EX_USAGE;
	}
	int ret = EX_OK;
	while (++argv, --argc > 0) {
		int fd = open(*argv, O_RDONLY);
		if (fd < 0) {
			error(0, errno, "%s", *argv);
			ret = ret ?: EX_NOINPUT;
			continue;
		}
		if (posix_fadvise(fd, 0, 0, POSIX_FADV_DONTNEED) < 0) {
			error(0, errno, "%s: posix_fadvise", *argv);
			ret = EX_OSERR;
		}
		if (close(fd) < 0)
			error(EX_OSERR, errno, "%s: close", *argv);
	}
	return ret;
}