Stdout does not work after using freopen

[waynejfoster]

I'm using freopen to redirect stdin and stderr to files
the redirection is fine. The problem arises when I use
fclose to close the streams. This causes stdout to fail.

In the example below you will see the loop of 1000000
doing fprintf(stdout,"HELLO\n"
after redirection should have finished.

I don't get anything printing to the screen as I would have
expected. How do I restore stdout and stderr streams back
to the original state to enable me to carry on printing to the screen.

// redirect stdout to tmp_file for GCC output
if(!(stream=freopen(tmp_name,"a",stdout))){
fprintf(stderr,"Can't redirect stdout for GCC\n"
exit(EXIT_FAILURE);
}
// redirect stderr to tmp for GCC error output
if(!(estream=freopen(tmp_e_name,"a",stderr))){
fprintf(stderr,"Can't redirect stdout for GCC\n"
exit(EXIT_FAILURE);
}

// spawn command for GCC
_spawnlp(_P_WAIT,"gcc.exe","gcc.exe","-E","-I",library,in_name,NULL);
fclose(stream);
fclose(estream);

// THIS BIT DOES NOT PRINT TO THE SCREEN AS WOULD BE EXPECTED, WHY???

for(i=0;i<10000000;i++){
fprintf(stdout,&quot;HELLO\n&quot;
}

 

[waynejfoster]

It's ok i've found a solution.

using _dup to preseve the stdout and stderr handles

_dup2 to force the stdout and stderr to pointer to the
file handle in question

then _dup2 at the end to restore then old handles

so there yah go...