#include <ext4.h> char *errno2s(int err){	switch(err){	case EROFS:	case EPERM:	case EACCES:    return "permission denied";	case ENOMEM:    return "out of memory";	case ENOENT:    return "file not found";	case EISDIR:    return "is a directory";	case EIO:       return "i/o error";	case ENODEV:	case ENXIO:     return "no such device";	case E2BIG:     return "argument list too long";	case EFAULT:    return "bad address";	case EEXIST:    return "file exists";	case ENOTDIR:   return "not a directory";	case EINVAL:    return "invalid argument";	case EFBIG:     return "file too large";	case ENOSPC:    return "no space left on device";	case EMLINK:    return "too many links";	case ERANGE:    return "math result not representable";	case ENOTEMPTY: return "directory not empty";	case ENODATA:   return "no data available";	case ENOTSUP:   return "not supported";	} 	return "???";}