这篇文章继续介绍一下socat的工作原理和选项说明。
工作原理
socat主要的工作原理如下所示：
工作原理说明：在初始化阶段解析命令行和初始化操作，然后顺次打开需要进行数据转发的两个连接，连接打开之后按照需要进行数据的转发，转发完毕关闭连接。
命令介绍
socat命令执行非常简单，格式如下所示：
命令格式：socat [options]
<address> <address>
options选项
| 选项 | 详细说明 |
|---|---|
| -V | print version and feature information to stdout, and exit |
| -h | -? |
| -hh | like -h, plus a list of all common address option names |
| -hhh | like -hh, plus a list of all available address option names |
| -d[ddd] | increase verbosity (use up to 4 times; 2 are recommended) |
| -D | analyze file descriptors before loop |
| -ly[facility] | log to syslog, using facility (default is daemon) |
-lf<logfile> |
log to file |
| -ls | log to stderr (default if no other log) |
| -lm[facility] | mixed log mode (stderr during initialization, then syslog) |
-lp<progname> |
set the program name used for logging |
| -lu | use microseconds for logging timestamps |
| -lh | add hostname to log messages |
| -v | verbose data traffic, text |
| -x | verbose data traffic, hexadecimal |
-b<size_t> |
set data buffer size (8192) |
| -s | sloppy (continue on error) |
-t<timeout> |
wait seconds before closing second channel |
-T<timeout> |
total inactivity timeout in seconds |
| -u | unidirectional mode (left to right) |
| -U | unidirectional mode (right to left) |
| -g | do not check option groups |
-L<lockfile> |
try to obtain lock, or fail |
-W <lockfile> |
try to obtain lock, or wait |
| -4 | prefer IPv4 if version is not explicitly specified |
| -6 | prefer IPv6 if version is not explicitly specified |
address说明
socat核心功能用于实现socket的转换，在命令行格式中的address所支持的主要类型包括：
- STDIN STDOUT ：标准输入输出
- 文件类型：可以指定文件作为数据流参数
- TCP类型：支持TCP类型
- UDP类型：支持UDP类型
- TCP-LISTEN：支持建立TCP监听端口
- UDP-LISTEN：支持建立UDP监听端口
- EXEC：支持程序的执行
