我会建议你设置一个信号处理程序,它在子进程产生输出时被调用。例如。您必须连接到readyReadStandardOutput
。
然后,您可以识别子流程何时需要输入并发送所需的输入。这将在readSubProcess()
完成。
的main.cpp
#include <QtCore>
#include "Foo.h"
int main(int argc, char **argv) {
QCoreApplication app(argc, argv);
Foo foo;
qDebug() << "Starting main loop";
app.exec();
}
在下文中,子进程启动和输入检查。当calculator
程序结束时,主程序也退出。
foo.h中
#include <QtCore>
class Foo : public QObject {
Q_OBJECT
QProcess myprocess;
QString output;
public:
Foo() : QObject() {
myprocess.start("./calculator");
// probably nothing here yet
qDebug() << "Output right after start:"
<< myprocess.readAllStandardOutput();
// get informed when data is ready
connect(&myprocess, SIGNAL(readyReadStandardOutput()),
this, SLOT(readSubProcess()));
};
private slots:
// here we check what was received (called everytime new data is readable)
void readSubProcess(void) {
output.append(myprocess.readAllStandardOutput());
qDebug() << "complete output: " << output;
// check if input is expected
if (output.endsWith("type\n")) {
qDebug() << "ready to receive input";
// write something to subprocess, if the user has provided input,
// you need to (read it and) forward it here.
myprocess.write("hallo back!\n");
// reset outputbuffer
output = "";
}
// subprocess indicates it finished
if (output.endsWith("Bye!\n")) {
// wait for subprocess and exit
myprocess.waitForFinished();
QCoreApplication::exit();
}
};
};
子进程计算器一个简单的脚本使用。你可以看到哪里输出产生和输入是预期的。
#/bin/bash
echo "Sub: Im calculator!"
# some processing here with occasionally feedback
sleep 3
echo "Sub: hallo"
sleep 1
echo "Sub: type"
# here the script blocks until some input with '\n' at the end comes via stdin
read BAR
# just echo what we got from input
echo "Sub: you typed: ${BAR}"
sleep 1
echo "Sub: Bye!"
如果您不需要做任何事情在你的主进程(如显示GUI,管理其他线程/进程....),最简单的是只在sleep
在后一个循环子流程创建,然后像readSubprocess
。
_I已经尝试了一些解决方案_显示你已经尝试过。 – 2017-09-26 18:47:03
通过连接信号和插槽:connect(process,SIGNAL(readyRead()),this,SLOT(readStdOut())); – Daud