FIFO pipe only reads after write end has closed

Question

I\'m trying to create a FIFO pipe between a python file and C file, but the issue is that when reading in the input from the C file, getline blocks until the writer end (in

Answer 1

Your problem comes from the buffer. FIFO use block buffer by default. So the c program won't read anything until the write buffer of the fifo in python was full. And there's two way to change this behaviour:

• specify the buffer mode:

there's three buffer mode:

1. block buffer(default)
2. line buffer
3. no buffer at all

What meet your needs here is the line buffer, so use fifo = open("emg", "w", 1); instead of fifo = open("emg", "w"); will fix. number 1 here instead line buffer. python doc

• another method is force flush the buffer, use fifo.flush after the write operation.