Consider b.nim:
let x = stdin.readLine()
echo("Got it: " & x)
echo("#done")
let y = stdin.readLine()
echo("Got another one: " & y)
echo("#done")
Run
and a.nim:
import osproc, streams
from strutils import contains
let p = startProcess("./b")
proc read(ous: Stream) =
var line: string
while not line.contains("#done"):
line = string(ous.readLine())
echo "READ: " & line
echo "MSG1"
p.inputStream.writeLine("A")
echo "Listening for MSG1 answer..."
read(p.outputStream)
echo "MSG2"
p.inputStream.writeLine("B")
echo "Listening for MSG2 answer..."
read(p.outputStream)
Run
The output stream(and the outputHandle) doesn't seem to work properly:
* this won't be able to read even the first #done because the stream drops
the output for some reason
* in another try I was able to read the first message - because the other
program started to respond much slower - but the got stuck again at the next
* if I do it with a reader thread then it can print every line but it seems
like the process is time-sensitive which means I can't use locks safely
