I have a C++ program that displays a lot of information in the dos box, all this information is needed to refer back to, to make adjustments. basicly is there a way of capturing everything in the dos box and directing it at a file. I cant use standard output as this does not work for some reason.
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CAN BurtanI OR anyone help with capturing everything in the dos box!!!
- Thread starter pilg
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greatkingrat
Programmer
If your program is a win32 console mode application,
you can redirect standard output stream by using 'dup2'.
dup( fd, 1 );
will redirects standard output to file 'fd'.
Hee S. Chung
heesc@netian.com
you can redirect standard output stream by using 'dup2'.
dup( fd, 1 );
will redirects standard output to file 'fd'.
Hee S. Chung
heesc@netian.com
greatkingrat
Programmer
Sorry, I made a slight mistake...
dup( fd, 1 ); ----> dup2( fd, 1 )
And an example code for dup2 is
/* dup2 sample */
#include <stdio.h>
#include <io.h>
int main( void )
{
FILE* fp = fopen( "myfile", "w" );
if( fp ) {
/* reserve old stdout */
int oldstdout = dup(1);
/* redirect stdout */
dup2( fileno(fp), 1 );
/* the following message will be written in the file 'myfile' */
puts( "My favorite musician is Freddie Mercury..." );
/* flush intermediate buffer for standard output */
fflush( stdout );
fclose( fp );
/* recover old stdout */
dup2( oldstdout, 1 );
/* the following message will be printed in the screen */
puts( "He is the greatest musician!" );
}
return 0;
}
/* end of source */
You can check the return value of dup or dup2 because it returns -1 if it is failed.
I wonder this function can help you...
Hee S. Chung
heesc@netian.com
dup( fd, 1 ); ----> dup2( fd, 1 )
And an example code for dup2 is
/* dup2 sample */
#include <stdio.h>
#include <io.h>
int main( void )
{
FILE* fp = fopen( "myfile", "w" );
if( fp ) {
/* reserve old stdout */
int oldstdout = dup(1);
/* redirect stdout */
dup2( fileno(fp), 1 );
/* the following message will be written in the file 'myfile' */
puts( "My favorite musician is Freddie Mercury..." );
/* flush intermediate buffer for standard output */
fflush( stdout );
fclose( fp );
/* recover old stdout */
dup2( oldstdout, 1 );
/* the following message will be printed in the screen */
puts( "He is the greatest musician!" );
}
return 0;
}
/* end of source */
You can check the return value of dup or dup2 because it returns -1 if it is failed.
I wonder this function can help you...
Hee S. Chung
heesc@netian.com
frankiecifarra
Programmer
Hi,
I want to know if this dup construction could be applied for input, I mean, that if an app that read data from keyboard would read data from a file instead and whether such a manipulation could be imposed from a parent process.
I want to know if this dup construction could be applied for input, I mean, that if an app that read data from keyboard would read data from a file instead and whether such a manipulation could be imposed from a parent process.
greatkingrat
Programmer
Sure,
dup2( fileno(fp), 0 );
will do that.
Hee S. Chung
heesc@netian.com
dup2( fileno(fp), 0 );
will do that.
Hee S. Chung
heesc@netian.com
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