how to print on screen in realtime

[zl2k]

hi, all
I am trying to moniter the runing of a program by printing out some
characters in a line at each stage. say,

//program part1
cout<<"part1 ";
//program part2
cout<<part2 ";
....

I was expecting the program will pring "part1 part2 part3 part4 ...."
in realtime but instead it only print out when the program is finished.
I force it to print out by adding <<endl for each cout then the output
turns to vertical which is hard to see. My question is, how may I print
it in a line in realtime? Thanks.

zl2k

 

[Victor Bazarov]

hi, all
I am trying to moniter the runing of a program by printing out some
characters in a line at each stage. say,

//program part1
cout<<"part1 ";
//program part2
cout<<part2 ";
...

I was expecting the program will pring "part1 part2 part3 part4 ...."
in realtime but instead it only print out when the program is
finished. I force it to print out by adding <<endl for each cout then
the output turns to vertical which is hard to see. My question is,
how may I print it in a line in realtime? Thanks.

Read about 'flush' manipulator. If it doesn't work, use your platform's
capabilities instead.

V

 

[Adi]

cout << flush;
cout.flush();
cout << endl;

This will flush the buffered output to be printed. The output is
buffered and will be printed when it reaches a limit or when the
program ends or some other condition like that.

Adi

 

[Marcus Kwok]

I am trying to moniter the runing of a program by printing out some
characters in a line at each stage. say,

//program part1
cout<<"part1 ";
//program part2
cout<<part2 ";
...

I was expecting the program will pring "part1 part2 part3 part4 ...."
in realtime but instead it only print out when the program is finished.
I force it to print out by adding <<endl for each cout then the output
turns to vertical which is hard to see. My question is, how may I print
it in a line in realtime? Thanks.

I don't know about "realtime", but you can try adding std::flush instead
of std::endl.

// program part1
cout << "part1 " << flush;
// program part2
cout << "part2 " << flush;

 

[Robbie Hatley]

I am trying to moniter the runing of a program by printing out some
characters in a line at each stage. say,

//program part1
cout<<"part1 ";
//program part2
cout<<part2 ";
...

I was expecting the program will pring "part1 part2 part3 part4 ...."
in realtime but instead it only print out when the program is finished.
I force it to print out by adding <<endl for each cout then the output
turns to vertical which is hard to see. My question is, how may I print
it in a line in realtime? Thanks.

As Victor Bazarov rightly pointed out, you can use flush at each point
where you want to force output, like so:

//program part1
cout << "part1 " << flush;
//program part2
cout << "part2 " << flush;

Another thing you can use is the "endl" manipulator, which first
prints an endline character ('\n'), then flushes the stream.
I tend to write text a line at a time in my progrms with immediate
output, like so:


//program part1
cout << "part1" << endl;
//program part2
cout << "part2" << endl;

which prints:

part1
part2
part3
etc.

in real-time.

I just thought I'd mention that option.


--
Cheers,
Robbie Hatley
East Tustin, CA, USA
lone wolf intj at pac bell dot net
(put "[usenet]" in subject to bypass spam filter)
http://home.pacbell.net/earnur/

 

[Marcus Kwok]

Another thing you can use is the "endl" manipulator, which first
prints an endline character ('\n'), then flushes the stream.
I tend to write text a line at a time in my progrms with immediate
output, like so:


//program part1
cout << "part1" << endl;
//program part2
cout << "part2" << endl;

which prints:

part1
part2
part3
etc.

in real-time.

I just thought I'd mention that option.

The OP had already considered that option but found the output to be too
hard to see.