call one perl script within another

[Ramprasad A Padmanabhan]

How Can I call a perl script within my main script

If I do

$response=`perl $somescript $args`;
This will call a new perl process, and may be more expensive on the
system. On the other hand I can do

do "$somescript $args";

But How do I get the reponse of the script.

Is there a way or should I just use the backticks
Thanks
Ram

[Andrew Shitov]

> This will call a new perl process, and may be more expensive on the

> system. On the other hand I can do

<...>

> But How do I get the reponse of the script.

Probably the simpliest way is to make called script a module and run it
using either 'use' or 'require'.

[Ramprasad A Padmanabhan]

Andrew Shitov wrote:

>> This will call a new perl process, and may be more expensive on the
>> system. On the other hand I can do

>
> <...>
>

>> But How do I get the reponse of the script.

>
>
> Probably the simpliest way is to make called script a module and run it
> using either 'use' or 'require'.
>

Precisely , But That is something I cannot do because the script is in a
file which is written on the fly by the client end settings.

Ideally it should have been such a way that The client settings are
written into a configuration file and the program reads the
configuraton file and runs the condition.

The point over here is , Is it possible to use the existing instance of
perl running main to run the child program and return the output

THanks
Ram

[Andrew Shitov]

my $return_value = eval {$code_or_sub_programme};

[Randal L. Schwartz]

>>>>> "David" == David Van Der Geer <David.vanderGeer@axa.nl> writes:

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[Wiggins D Anconia]

> Andrew Shitov wrote:

> >> This will call a new perl process, and may be more expensive on the
> >> system. On the other hand I can do

> >
> > <...>
> >

> >> But How do I get the reponse of the script.

> >
> >
> > Probably the simpliest way is to make called script a module and run it
> > using either 'use' or 'require'.
> >

>
> Precisely , But That is something I cannot do because the script is in a
> file which is written on the fly by the client end settings.
>
> Ideally it should have been such a way that The client settings are
> written into a configuration file and the program reads the
> configuraton file and runs the condition.
>
> The point over here is , Is it possible to use the existing instance of
> perl running main to run the child program and return the output
>

'require' is runtime not compile time, so assuming you can regulate the
sequence of events, aka the file is known to be written (or testable in
a loop) before the call to require then this will still work even if the
file does not exist at runtime. If you are worried about the require
failing because of a missing file then wrap the whole construct in an
'eval' and catch the exceptions (which you should do anyways).

.... still isn't a compelling reason to call one Perl script from another...

[url]http://danconia.org[/url]

[Dan Anderson]

I think there's a function called eval which lets you evaluate perl code
on the fly. [url]http://www.perldoc.com/perl5.8.0/pod/func/eval.html[/url]

-Dan

[Rick Edwards]

System will fork a second shell process from the parent and wait for a
response when the child process exits (which sounds like what you want).
This is not so efficient as exec which kills the parent process.

For system:

my $return = system (my_script, my_argument);

Will start a child process and wait until it completes returning an exit
value.

Regards

Rick

Dr Richard Edwards, Web Developer
Sift, 100 Victoria Street, Bristol, BS1 6HZ, UK
Tel: +44 117 9159600 Fax: +44 117 9159630
[url]http://www.sift.co.uk[/url]


-----Original Message-----
From: Geer, David van der [mailto:David.vanderGeer@axa.nl]
Sent: 21 October 2003 08:03
To: Ramprasad A Padmanabhan; [email]beginners@perl.org[/email]
Subject: RE: call one perl script within another

> How Can I call a perl script within my main script
> If I do
> $response=`perl $somescript $args`;

This will fork and open a shell so is slow

> do "$somescript $args";
> But How do I get the reponse of the script.
> Is there a way or should I just use the backticks

Please look at system() and exec() this should help you out.

Regs David

> Thanks
> Ram

[ramya]

When i am running the below program i got the error as permission denied
/usr/bin/perl -w
print ”this is calling script \n ";
system "/myhome/caller_script.pl”;
exit;
I need to write a script that should call another script
pls help me.