在MySQL的使用过程中遇见很多错误，比如由于操作系统引起的，文件或目录不存在，或SQL语句错误引起的。这些error会有相应的代码：error#，Errcode#。"#"代表具体的错误号。perror可以查看这些错误的详细内容。
查看perror的使用方法：
[root@YANG mysql]# perror
perror Ver 2.10, for pc-linux-gnu (i686)
This software comes with ABSOLUTELY NO WARRANTY. This is free software,
and you are welcome to modify and redistribute it under the GPL license
Print a description for a system error code or an error code from
a MyISAM/ISAM/BDB table handler.
If you want to get the error for a negative error code, you should use
-- before the first error code to tell perror that there was no more options.
Usage: perror [OPTIONS] [ERRORCODE [ERRORCODE...]]
-?, --help Displays this help and exits.
-I, --info Synonym for --help.
--ndb Ndbcluster storage engine specific error codes.
-s, --silent Only print the error message.
-v, --verbose Print error code and message (default).
-V, --version Displays version information and exits.
Variables (--variable-name=value)
and boolean options {FALSE|TRUE} Value (after reading options)
--------------------------------- -----------------------------
ndb FALSE
verbose TRUE
[root@YANG mysql]# perror 30 60
OS error code 30: Read-only file system
OS error code 60: Device not a stream