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I'm trying to get the stdout of a process via POPEN as soon as it's there. With gevent 1.0 readline() and read() still block process and wait for process to finish. Any clues? And yes, I searched high and low for a simple solution. It has to be possible without threading, right? import gevent from gevent.subprocess import Popen, PIPE def cron(): while True: print("cron") gevent.sleep(0.5) g = gevent.spawn(cron) def subp(): sub = Popen('sleep 1; ping www.google.com -c 2; sleep 5; uname', stdout=PIPE, shell=True) while True: s = sub.stdout.readline() if s == "": break else: print s.strip() g

In this C program #include <stdio.h> #include <fcntl.h> int main() { int file = open("Result", O_CREAT|O_WRONLY, S_IRWXU); dup2(stdout, file); system("ls -l"); return 0; } I'm trying to redirect the output of system() to a file, for that i have used dup2 but it is not working. What's wrong with this code ? and, please tell me if there is any better way to do this ? (without using > at the terminal ) stdout is a FILE * pointer of the standard output stream. dup2 expects file descriptor, also you've messed up the parameters order. Use dup2(file, 1); instead. On the better-way-to-do-this part.

How do I launch an app and capture the output via stdout and maybe stderr? I am writing an automated build system and I need to capture the output to analyze. I'd like to update the svn repo and grab the revision number so I can move the files in autobuild/revNumber/ if successful. I also would like to build using make and upload the compile text to my server for everyone to see the warnings and errors on a failed build. I can't find the system() function, but I found the CreateProcess() function on MSDN. I am able to launch what I need but I have no idea how to capture the stderr and stdout.

Out of curiosity, is it possible to create, instantiate, or otherwise access additional output buffers besides STDOUT and STDERR from within a Perl script? The use case would be additional outputs to pipe in to files or other commands, eg ./doublerainbow.pl 3>full_on.txt 4>all_the_way!.txt mob Absolutely. The open command with the >&= mode allows you to open filehandles on arbitrary file descriptors. # perl 4fd.pl > file1 2> file2 3> file3 4> file4 5< file5 open STDFOO, '>&=3'; open STDBAR, '>&=4'; open STDBAZ, '<&=5'; # works for input handles, too print STDOUT "hello\n"; print STDERR "world

Say I have a function like below, how do I capture the output of the Process.spawn call? I should also be able to kill the process if it takes longer than a specified timeout. Note that the function must also be cross-platform (Windows/Linux). def execute_with_timeout!(command) begin pid = Process.spawn(command) # How do I capture output of this process? status = Timeout::timeout(5) { Process.wait(pid) } rescue Timeout::Error Process.kill('KILL', pid) end end Thanks. You can use IO.pipe and tell Process.spawn to use the redirected output without the need of external gem. Of course, only

Possible Duplicate: How to flush output of Python print? I have have an algorithm that I'm running that takes a while, so I want to keep track of how far it's through, by printing to the console. So something like: import sys def myMethod(): i = 0 while (i<1000000): i = i+1 output_str = str(i) + "\n" sys.stdout.write(output_str) # same as print sys.stdout.flush() myMethod() How can I have this print while it's running, rather than at the end? Edit, Solution: - Posted amended code. This code works fine when you run it in the linux terminal using python filename.py But when I run it in Wing 101

I'm using a grid engine to run R scripts. The STDERR is taken seriously under this setup, so I would like to keep it clean and have only real/serious/fatal errors printed to STDERR. The problem is my R script generate various STDERR messages which are not really serious warnings... for example, scan seems to print to STDERR the number of items it read. Can I redirect (from within R) STDERR to STDOUT? Look at the help page for sink() : ‘sink’ diverts R output to a connection. If ‘file’ is a character string, a file connection with that name will be established for the duration of the diversion.