Very Computer

#include <stdio.h>
#include <sys/types.h>
#include <unistd.h>
void main(void)
{
fork(); printf("hee\n");
fork(); printf("ho\n");

Quote:}

Got the inspiration from
John Shapley Gray's InterProcess Communications in Unix.

process 1
        | fork
        +--------->-------------------------  process 2
        | printf("hee\n")                     | printf("hee\n")
        v                               v
        | fork                          | fork
        +--------->-------  process 4        +-------->--------  process 3
        | printf("ho\n")      | printf("ho\n")      | printf("ho\n")      | printf("ho\n")
        |               |               |               |
        x exit          x exit          x exit          x exit

Output is one of the following, depending of the process scheduling:

        hee     hee     hee
        ho      ho      hee
        ho      hee     ho
        hee     ho      ho
        ho      ho      ho
        ho      ho      ho
--
Herve Couppe de Lahongrais (SEU)       | Eurocontrol Experimental Centre

Sorry,
Your answer is wrong.
I have run it under HP.

Quote:> Sorry,
> Your answer is wrong.
> I have run it under HP.

hee
ho
ho
hee
ho
ho

Quote:> void main(void)

During a brain fsck on Tue, 17 Jun 1997 17:51:39 +0800,  Land Transport

Quote:

>#include <stdio.h>
>#include <sys/types.h>
>#include <unistd.h>
>void main(void)
>{
>fork(); printf("hee\n");
>fork(); printf("ho\n");
>}

>How many lines of output do you expect to see ?
>I got it wrong . Need your help to understand this.

|__________
|          |
hee        hee
|_______   |_______    
|       |  |       |
ho      ho ho      ho

ho'pe this hee'lp s

--


Calcasieu Lumber Co.                        Austin TX
- If NT is the answer, you don't understand the question

: #include <stdio.h>
: #include <sys/types.h>
: #include <unistd.h>
: void main(void)
: {
: fork(); printf("hee\n");
: fork(); printf("ho\n");
: }
:
: How many lines of output do you expect to see ?
: I got it wrong . Need your help to understand this.
:
parent prints: hee
      |        ho
      |
      |
      |-- 1st child prints: hee
      |        |            ho
      |        |
      |        |-- 1st child kid prints: ho
      |
      |-- 2nd child prints: ho

 I think this will help you.

--
  GE/CS dx s-:- a-- C++ LU++ P+>++ L+++ E> W++ N++ K- w--- V
  PS+++ PE+ Y+ PGP t 5? X++++ R tv b+ DI? D+ G e h-- r z+>++
  |==================================|

  |==================================|

Herve Couppe de Lahongrais - CDL wrote ...

Quote:> Here is the execution diagram :

> process 1
>    | fork
>    +--------->-------------------------  process 2
>    | printf("hee\n")                     | printf("hee\n")
>    v                               v
>    | fork                          | fork
>    +--------->-------  process 4        +-------->--------  process 3
>    | printf("ho\n")      | printf("ho\n")      | printf("ho\n")      | printf("ho\n")
>    |               |               |               |
>    x exit          x exit          x exit          x exit

> Output is one of the following, depending of the process scheduling:

>    hee     hee     hee
>    ho      ho      hee
>    ho      hee     ho
>    hee     ho      ho
>    ho      ho      ho
>    ho      ho      ho

I was under the impression that the child should call _exit() and not
exit()
to guarantee sanity. Isn't this in the FAQ?

Richard.

--
Herve Couppe de Lahongrais (SEU)       | Eurocontrol Experimental Centre

warning. dont RUN this on a live machine.

can you spell "c-r-a-s-h-" ?

Quote:> #include <stdio.h>
> #include <sys/types.h>
> #include <unistd.h>
> void main(void)
> {
> fork(); printf("hee\n");
> fork(); printf("ho\n");
> }

> How many lines of output do you expect to see ?
> I got it wrong . Need your help to understand this.

> Got the inspiration from
> John Shapley Gray's InterProcess Communications in Unix.

: #include <stdio.h>
: #include <sys/types.h>
: #include <unistd.h>
: void main(void)
: {
: fork(); printf("hee\n");
: fork(); printf("ho\n");
: }
:
: How many lines of output do you expect to see ?
: I got it wrong . Need your help to understand this.
:

        Hi,
                I ran it under DRS/6000.
                Got the following output :
                hee
                hee
                ho
                ho
                ho
                ho

--
|-------------------------------------------------------------------------|
|  It is hard to think of you as product     (Chandrashekhar P.Bhide)     |

|-------------------------------------------------------------------------|

Indeed a puzzle,
I ran the program in a loop directing the output to files and each file
was different.
for i in 1 2 3 4 5 6
do
 tstfork > $i
done

some of the files had 2 hee's and 4 ho's as they should have, but some
had only 1 hee and 3 ho's and all other combination

Quote:> #include <stdio.h>
> #include <sys/types.h>
> #include <unistd.h>
> void main(void)
> {
> fork(); printf("hee\n");
> fork(); printf("ho\n");
> }
> How many lines of output do you expect to see ?
> I got it wrong . Need your help to understand this.
> Got the inspiration from
> John Shapley Gray's InterProcess Communications in Unix.

Quote:>#include <stdio.h>
>#include <sys/types.h>
>#include <unistd.h>
>void main(void)
>{
>fork(); printf("hee\n");
>fork(); printf("ho\n");
>}
>How many lines of output do you expect to see ?
>I got it wrong . Need your help to understand this.

But if the output is fully buffered, you'd get 4 hee's as each the
output buffers are flushed multiple times.  (The second fork will
effectively cause a doubling of hee's)
Adding "fflush(stdout)" before each fork() should remedy that.

Casper
--
Expressed in this posting are my opinions.  They are in no way related
to opinions held by my employer, Sun Microsystems.
Statements on Sun products included here are not gospel and may
be fiction rather than truth.

Quote:

> #include <stdio.h>
> #include <sys/types.h>
> #include <unistd.h>
> void main(void)
> {
> fork(); printf("hee\n");
> fork(); printf("ho\n");
> }

> How many lines of output do you expect to see ?

Quote:> I got it wrong . Need your help to understand this.

Your process splits into 4.  Each of these processes has built up a
stdout buffer containing "hee\nho\n".  Each will flush this as they
exit.  Since this string is short the outputs from the 4 processes
will not get interleaved.  You'll see:

hee
ho
hee
ho
hee
ho
hee
ho

--

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