Nothing complex here, just have in mind that the last command should output to the original process’ file descriptor 1 and the first should read from original process file descriptor 0. You just spawn the processes in order, carrying along the input side of the previous pipe call. So, here’s are the types: #include <unistd.h> … Read more
I just found out a simpler answer to part of my question. To quickly and synchronously detect if piped content is being passed to the current script in Node.js, use the process.stdin.isTTY boolean: $ node -p -e ‘process.stdin.isTTY’ true $ echo ‘foo’ | node -p -e ‘process.stdin.isTTY’ undefined So, in a script, you could do … Read more
Update (as I can’t delete the accepted answer): the proper solution is to implement a custom demuxer, similar to the concat one. There’s currently no other clean way. You have to get your hands dirty and code! Below is an ugly hack. This is a very bad way to do it, just don’t! The solution … Read more
I found out how to do it. It is not about threads, and not about select(). When I run the first process (grep), it creates two low-level file descriptors, one for each pipe. Lets call those a and b. When I run the second process, b gets passed to cut sdtin. But there is a … Read more
You can also cancel/end a pipe by using a signal Subject and the rxjs operator: takeUntil Example httpGetSafe(path: string): Observable<Data> { const stopSignal$ = new Subject(); return this.http.get<Data>(path).pipe( map(data => { const isBad = data === null; if (isBad) { stopSignal$.next(); } return data; }), takeUntil(stopSignal$) ); } Sometimes it’s a bit simpler and more … Read more
In order to be able to use a pipe, you need to execute a shell command, i.e. the command with the pipeline has to be a single command for -exec. find /path/to/dir -type f -print -exec sh -c “cat {} | head -1 | grep yourstring” \; Note that the above is a Useless Use … Read more
Try this: import sys import time k = 0 try: buff=”” while True: buff += sys.stdin.read(1) if buff.endswith(‘\n’): print buff[:-1] buff=”” k = k + 1 except KeyboardInterrupt: sys.stdout.flush() pass print k