Lost line with QProcess

I am having problems with the following short program I wrote with Qt 4.1.2

Code:

---

#include <QString>
#include <iostream>
#include <QProcess>
 
using namespace std;
 
void ProcessLine( QString );
 
int main()
{
    QProcess *gzip = new QProcess;
    QString line;
    gzip->start("gunzip in.txt.gz -c");
 
    while (gzip->waitForReadyRead()) {
       while (gzip->canReadLine()) {
            line = gzip->readLine();
           ProcessLine( line );
       }
    }
}
 
void ProcessLine( QString line ) {
   cout << line.toStdString();
}

---

my test file in.txt.gz contains the following all zipped
this is a test 1
this is a test 2
this is a test 3
this is a test 4
this is a test 5
this is a test 6
this is a test 7
this is a test 8

when I compile and run my code I get the following output.
this is a test 2
this is a test 3
this is a test 4
this is a test 5
this is a test 6
this is a test 7
this is a test 8

Notice that I have somehow lost the first line of the file.
every once in a while I do end up getting the first line.

Can someone Please tell me what's happing to the first line?
What is wrong with my code?

Try put \n before first line :rolleyes:

Try doing it the proper way -- connect the readyReadStandardOutput() signal from your process to a slot and read the data there, and don't read a single line, but rather all of them at once.

Code:

---

QProcess *process = new QProcess(...);
connect(process, SIGNAL(readyReadStandardOutput ()), this, SLOT(fetchOutput()));
connect(process, SIGNAL(finished ( int, QProcess::ExitStatus )), this, SLOT(fetchRest()));
process->start("...");
//...
 
void thisClass::fetchOutput(){
  QProcess *proc = (QProcess*)sender();
  while(proc->canReadLine()){
    cout << proc->readLine().constData() << endl;
  }
}
 
void thisClass::fetchRest(){
  QProcess *proc = (QProcess*)sender();
  cout << proc->readAllStandardOutput().constData();
}

---