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Hello All,
The perl documentation says the fork command generates two copies of the
program ,one parent and one child.
If this is correct,can this fork command be used for multitasking?.

rajendra <> wrote in comp.lang.perl.misc:
> Hello All,
> The perl documentation says the fork command generates two copies of the
> program ,one parent and one child.
> If this is correct,can this fork command be used for multitasking?.

Yes, that is its very purpose.

Anno

On Thu, 26 Jul 2007 15:43:24 +0530, "rajendra"
<> wrote:

>The perl documentation says the fork command generates two copies of the
>program ,one parent and one child.
>If this is correct,can this fork command be used for multitasking?.

Well, yes: but what do you mean exactly? AIUI multitasking is better
seen as a property of "some" osen and fork() is one way to use it to
one's advantage...


Michele
--
{$_=pack'B8'x25,unpack'A8'x32,$a^=sub{pop^pop}->(map substr
(($a||=join'',map--$|x$_,(unpack'w',unpack'u','G^<R<Y]*YB='
..'KYU;*EVH[.FHF2W+#"\Z*5TI/ER<Z`S(G.DZZ9OX0Z')=~/./g)x2,$_,
256),7,249);s/[^\w,]/ /g;$ \=/^J/?$/:"\r";print,redo}#JAPH,

rajendra wrote:
> The perl documentation says the fork command generates two copies of
> the program ,one parent and one child.

Well, no. It creates _one_ additional copy of the running process, commonly
known as child process.

> If this is correct,can this fork command be used for multitasking?.

That is its main purpose, yes.

jue

On 26 Jul 2007 11:29:14 GMT wrote:

a> rajendra <> wrote in comp.lang.perl.misc:
>> The perl documentation says the fork command generates two copies of the
>> program ,one parent and one child.
>> If this is correct,can this fork command be used for multitasking?.

a> Yes, that is its very purpose.

I usually point people to the Stevens books (Advanced Programming in the
Unix Environment 2nd ed., especially) or some equivalent tutorial,
whenever they ask about fork(). I think using fork() requires
understanding the way it works on the OS level--at least IPC and IO
stream behavior, if nothing else.

Ted

Ted Zlatanov <> wrote in comp.lang.perl.misc:
> On 26 Jul 2007 11:29:14 GMT wrote:
>
> a> rajendra <> wrote in comp.lang.perl.misc:
> >> The perl documentation says the fork command generates two copies of the
> >> program ,one parent and one child.
> >> If this is correct,can this fork command be used for multitasking?.
>
> a> Yes, that is its very purpose.
>
> I usually point people to the Stevens books (Advanced Programming in the
> Unix Environment 2nd ed., especially) or some equivalent tutorial,

Just for the record, _Advanced Programming in the Unix Environment_
itself is *not* a tutorial but a hard-core reference.

Anno

One more query:
Can I use a variable common to both child and parent process block?.
"rajendra" <> wrote in message
news:f89s46$i07$...
> Hello All,
> The perl documentation says the fork command generates two copies of the
> program ,one parent and one child.
> If this is correct,can this fork command be used for multitasking?.
>
>
>

rajendra <> wrote in comp.lang.perl.misc:
> One more query:
> Can I use a variable common to both child and parent process block?.

You can. Note that the same name addresses different variables in
the parent and the child. They will have the same initial value in
both, but changes in one don't reflect in the other.

Anno

If i want to update(modify) a in both child and parent process, how can I do
this?....
<> wrote in message
news:...
> rajendra <> wrote in comp.lang.perl.misc:
> > One more query:
> > Can I use a variable common to both child and parent process block?.
>
> You can. Note that the same name addresses different variables in
> the parent and the child. They will have the same initial value in
> both, but changes in one don't reflect in the other.
>
> Anno

On Mon, 30 Jul 2007 17:12:06 +0530, "rajendra"
<> wrote:

>If i want to update(modify) a in both child and parent process, how can I do
>this?....

You must establys some sort of IPC between them. Read

perldoc perlipc

to find out some ways to do so.


Michele
--
{$_=pack'B8'x25,unpack'A8'x32,$a^=sub{pop^pop}->(map substr
(($a||=join'',map--$|x$_,(unpack'w',unpack'u','G^<R<Y]*YB='
..'KYU;*EVH[.FHF2W+#"\Z*5TI/ER<Z`S(G.DZZ9OX0Z')=~/./g)x2,$_,
256),7,249);s/[^\w,]/ /g;$ \=/^J/?$/:"\r";print,redo}#JAPH,