stop output from apperaring from stdout and stderr

[pranav.choudhary]

Hi,
In my C program, i fork a new process and use exec to execute a new
program in the child process. But i don't want the child process to
write anything to the stdout or stderr. How can i do that?

--pranav

 

[Flash Gordon]

Hi,
In my C program, i fork a new process and use exec to execute a new
program in the child process. But i don't want the child process to
write anything to the stdout or stderr. How can i do that?

In standard C you can't, you also can't fork or exec. Try a group
dedicated to your system such as comp.unix.programmer

 

[selvesteen]

In standard C you can't, you also can't fork or exec. Try a group
dedicated to your system such as comp.unix.programmer

Please note that The exec*() system calls, in all their forms, loads a
program from an ordinary, executable file into the current process,
replacing the current program. So the your child process have no
control on 'exec'- ed program. Instead you may redirect all the stdout
or stderr in exec-ed program.

 

[pranav.choudhary]

Can i redirect stdout and stderr to somthing NULL. If yes, how?

 

[Joe Estock]

Can i redirect stdout and stderr to somthing NULL. If yes, how?

Like you have already been told, try a newsgroup dedicated to your
operating system (comp.unix.programmer). We only deal with standard c
here and standard c knows nothing about stdout or stderr redirection.

<Semi-OT>
Now, if you want to close stdout and stderr that can be done as well.
Remember, stdout and stderr are both pointers to tyoe FILE * and can be
manipulated with fclose and friends.
</Semi-OT>

<OT>
Call fclose() on stdout and stderr from within the child pid when you
fork().
</OT>

If you need anymore help that doesn't pertain to standard c, please
visit the above mentioned newsgroup.


Joe

 

[Kenneth Brody]

Can i redirect stdout and stderr to somthing NULL. If yes, how?

Like you have already been told, try a newsgroup dedicated to your
operating system (comp.unix.programmer). We only deal with standard c
here and standard c knows nothing about stdout or stderr redirection. [...]
<OT>
Call fclose() on stdout and stderr from within the child pid when you
fork().
</OT>

[...]

Causing "bad things"[tm] to happen. Any printf()/sprintf(stderr) will
now cause undefined behavior. And, perhaps worse, the next fopen() may
return the same FILE* as was previously occupied by stdout/stderr, and
writing to stdout/stderr will now go to the fopen()ed file.

On the other hand, your platform may have the ability to freopen stdout
and stderr to a bit-bucket, such as Unix's "/dev/null".

Check a group related to your O/S for more details.

--
+-------------------------+--------------------+-----------------------------+
| Kenneth J. Brody | www.hvcomputer.com | |
| kenbrody/at\spamcop.net | www.fptech.com | #include <std_disclaimer.h> |
+-------------------------+--------------------+-----------------------------+
Don't e-mail me at: <mailto:[email protected]>