Re: the different effect of system call fork()

[Nick Andrew]

On Wed, Apr 08, 2009 at 03:08:48PM +0200, Bernd Petrovitsch wrote:
> >    if (pid_t pid = fork() < 0)
> 
> I don't think that this line does what you want it to do.
> Hint: Using a "pid_t" for the boolean result for a comparison seems
> strange at best.

The "problem" is due to a misunderstanding of C/C++ operator precedence.

"(pid = fork() < 0)" binds like "pid = (fork() < 0)" and so pid always
has a value of zero and so both parent and child process run the "first
level child process" code ... soon there are 4 processes all confused
about who they are.

Nick.
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