Unrecoverable read error on source.

源盘上不可恢复的读错误。

youdao

The read function returns the number of bytes read (up to the maximum that you specify), -1 on error, or zero if the end of the file has been reached.

read 函数返回读取的字节数（最高为您指定的最大值）；或者 -1，表示错误；或者 0，如果已经到达文件末尾。

youdao

Read should return exactly the number of bytes requested, except on EOF or error; otherwise, the rest of the data will be substituted with zeroes.

除非碰到EOF或出现错误，否则read应该返回所请求的字节数的数据；否则，其余数据都会被替换成0。

youdao

In order for the technology to work in practice, Bond says, it must be possible to read the chips on thousands of pill bottles at once--without error.

FORBES: Tiny Chips Could Combat Counterfeit Pills