Nonblocking IO (ITI8510): erinevus redaktsioonide vahel
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Mine otsikasti
| 5. rida: | 5. rida: | ||
Goal: To write a program which echoes characters on screen while typed until button 'q' is pressed. Then prints a newline. | Goal: To write a program which echoes characters on screen while typed until button 'q' is pressed. Then prints a newline. | ||
'''Hints:''' | |||
* Try to put the terminal into noncanonical mode. See 'man termios' or [ [http://www.google.ee/search?q=noncanonical+mode Google] for that. | |||
* Note that you should restore the terminal mode before quitting since otherwise the terminal might get messed up (no echo). | |||
= 2. Nonblocking reading from a FIFO = | = 2. Nonblocking reading from a FIFO = | ||
Redaktsioon: 18. veebruar 2010, kell 17:39
We have two tasks today. Both with practicing nonblocking IO.
1. Canonical mode
Goal: To write a program which echoes characters on screen while typed until button 'q' is pressed. Then prints a newline.
Hints:
- Try to put the terminal into noncanonical mode. See 'man termios' or [ Google for that.
- Note that you should restore the terminal mode before quitting since otherwise the terminal might get messed up (no echo).
2. Nonblocking reading from a FIFO
Goal: To write a program which prints a '.' character every half-a second unless some input is provided on a fifo file.
Hints:
- Use open() with O_NONBLOCK flag,
- FIFO can be made with a 'mkfifo fifoname' command and written to using 'cat > fifoname'.
- You have to open fifo before reading (use two terminals).
- It helps to set output to non-buffered mode (the default is line-buffered).