Lua API moved into a tio library table and names adjusted to Lua stdlib style.
Regex in expect() replaced with Lua patterns so binary data can be handled.
New tio.alwaysecho variable allows enabling and disabling echo to console.
Read and write functions now manage complex retry and timeout logic internally,
giving the user a simple "nil if fail" API like the rest of Lua.
exit() was removed, os.exit() already exists in the Lua standard library.
+ Add missing timestamp-format epoch
+ Update send_ to use fsync and tcdrain like normal tty_sync does
+ Rework read_line to save partial line at timeout
+ Simplified read_line to reduce cyclomatic complexity
+ renamed example files read.lua and read_line.lua
+ moved #define READ_LINE_SIZE to top of file
+ renamed g_linebuf to linebuf, and moved it into read_line as a static variable