基本上,我有以下代码段
#!/usr/bin/env python3
import os
import sys
import subprocess
import time
import shlex
import paho.mqtt.client as paho
if __name__ == "__main__":
r, w = os.pipe()
processId = os.fork()
if processId:
# wait to ensure tshark is started appropriately
os.
下面是脚本:
# Announce intent
puts "\nOpening a Pipe\n"
# and open a pipe to the ls command
set pipe [open "|ls /" "r"]
# Equivalent command under MS-Windows is:
# set pipe [open "!command.com /c dir" "r"]
# read the output of the ls command:
while {![eof $pipe]
当我在我的Mac (OS/X 10.6.4)上运行下面的程序时,我得到以下输出:
$ ./a.out
Read 66 lines of output from /bin/ps
Read 0 lines of output from /bin/ps
Read 0 lines of output from /bin/ps
Read 0 lines of output from /bin/ps
Read 0 lines of output from /bin/ps
为什么popen()只在我第一次调用它时读取数据,而随后的传递不返回任何输出?
#include <stdio.h>
i
我有两种执行bash脚本的tcl脚本:
#exec bash ./run.sh
open "|bash ./run.sh r"
bash脚本如下所示:
#!/bin/bash
ls
if [ "$?" != "0" ]; then
echo "ERROR: Status failed!" > status
else
echo "Everything is OK!" > status
fi
我使用tclsh for Windows和git bash中的bash。当我使用:
exec bas
我使用一个命名管道来捕获另一个程序(MATLAB)中的外部程序(wgrib2)的输出。MATLAB代码如下所示,system()访问命令行以生成管道:
system('mkfifo myfifo'); % Make a named pipe myfifo
% Call the external program wgrib2 and dump its output to the named pipe myfifo
system('wgrib2.exe multi_1.glo_30m.hs.201212.grb2 -ij 1 165 -ij 1 166 > m
我有一个进程,它将连续的字节流写入stdout。我有另一个进程,它从第一个进程的标准输出中读取,然后完成。但我发现,当第二个进程完成时,它会关闭管道(我认为),因此进程1停止运行。
我尝试了两种不同的方法:
在第1款中:
# make fifo
mkfifo /tmp/camera
# stream video from my webcam to the pipe
ffmpeg -y -f v4l2 -r 10 -i /dev/video0 -f avi /tmp/camera
在第2款中:
# attach to pipe and take a snapshot
rrmpeg -y -r 1