pipe question

Overworked_PhD · 08-17-2008, 04:51 PM

On page 502 in the book "Advanced Programming in the Unix Environment" by Stevens and Rago,
they have a the following function to help sychronize the parent and
child.

Code:

static int pfd1[2] , pfd2[2];

void
TELL_PARENT(pid_t pid)
{
    if (write(pfd2[1],  "c", 1) != 1)
        err_sys("write error");

}

What's the point of using pid if the function TELL_PARENT() doesn't
actually use it?

Codeplug · 08-17-2008, 05:57 PM

I think it's an attempt by the authors to confuse their readers.....or just an omission.

Check the errata for other "oops": http://www.apuebook.com/index.html

gg

Overworked_PhD · 08-17-2008, 06:05 PM

There's nothing about it in the errata.

08-17-2008, 04:51 PM	#1
Overworked_PhD Registered User Join Date: May 2007 Location: Berkeley, CA Posts: 140	pipe question On page 502 in the book "Advanced Programming in the Unix Environment" by Stevens and Rago, they have a the following function to help sychronize the parent and child. Code: static int pfd1[2] , pfd2[2]; void TELL_PARENT(pid_t pid) { if (write(pfd2[1], "c", 1) != 1) err_sys("write error"); } What's the point of using pid if the function TELL_PARENT() doesn't actually use it?
Overworked_PhD is offline

08-17-2008, 05:57 PM	#2
Codeplug Registered User Join Date: Mar 2003 Posts: 3,903	I think it's an attempt by the authors to confuse their readers.....or just an omission. Check the errata for other "oops": http://www.apuebook.com/index.html gg
Codeplug is offline

08-17-2008, 06:05 PM	#3
Overworked_PhD Registered User Join Date: May 2007 Location: Berkeley, CA Posts: 140	There's nothing about it in the errata.
Overworked_PhD is offline

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