Introduction - If you have any usage issues, please Google them yourself
|- P6.1.c access to standard input, output and error output terminal names |- p6.2.c modified sample terminal control characters |- p6.3.c realize the use of curses password |- p6. 4.c use tcgetattr function and realize tcsetattr function password |- p6.5.c serial read and write sample |- p6.6.c loudspeaker audible procedures |- p6.7.c use sound card to play audio files `- p6.8.c sound card recording procedures sample