How to redirect stdout to a file with fork-exec?

09-22-03, 10:22 AM

music4

Greetings,

I writing a fork-exec program as:

if ((pid = fork()) == 0)
{
// Question here: how a redirect exec-ing process's output to a file?

exec();
}
else if (pid > 0)
{
// Wait for exec-ed process terminated.
// Then read the output file.
}

Thanks in advance!
Evan

09-22-03, 10:58 AM

Nils O. Selåsdal

In article <bkmf2p$ji4>, music4 wrote:
> Greetings,
>
> I writing a fork-exec program as:
>
> if ((pid = fork()) == 0)
> {
> // Question here: how a redirect exec-ing process's output to a file?
int fd = open("filename",yourflags);
dup2(fd,STDOUT_FILENO);
cloes(fd);

If I remember correctly.. Probably you can use 2 instead of STDOUT_FILENO.
[..]

09-24-03, 09:02 PM

Barry Margolin

In article <slrnbmte9d.fto.noselasd>,
Nils O. Selåsdal <noselasd> wrote:
>In article <bkmf2p$ji4>, music4 wrote:
>> Greetings,
>>
>> I writing a fork-exec program as:
>>
>> if ((pid = fork()) == 0)
>> {
>> // Question here: how a redirect exec-ing process's output to a file?
> int fd = open("filename",yourflags);
> dup2(fd,STDOUT_FILENO);
> cloes(fd);
>
>If I remember correctly.. Probably you can use 2 instead of STDOUT_FILENO.

That wouldn't be a good idea, since 2 is stderr, not stdout.

Similar Threads
redirect powershell stdout to objShell.Exec.Stdout.ReadAll()( Hi, I have a similar problem I am dealing with. Hence posting in this discussion chain. I have a powershell script text.ps1 And then I have a .js file which is invoking...
How to use fork-exec system call to redirect stdout/stderr to a buffer? Hi there I am a beginner for system programming, I'd like to use fork-exec programming to perform a "C-code compilation" and see if any compilation errors within...
Redirect STDOUT and STDERR to file in ksh First up, apologies if this is a really dumb question ("There are no dumb questions, but there are a lot of inquisitive idiots")... I'm running a perl script which just...
Any standard way to fork and exec something that isn't in a file? That subject probably sounds non-sensical--bear with me. Here's what I want to do. In one program I want to load a file into memory that has been encrypted; decrypt it; and...
Redirect stdout, stderr to file and stdout I have a small script that does some admin work for me. What I need to do now is not only have is display information to STDERR and STDOUT but also write the same...