Solved

Sub Routine in a Variable ???

Posted on 2002-05-04
3
255 Views
Last Modified: 2010-03-05

I would like my Perl program to run a subroutine
that I have stored in a variable without having to
write it to disk. Is there a way to do that?The following doesn't work:

my $routine = "sub MySub{  print  \"hello from a sub in a variable!\";   }";

&$routine;

I get the following message:
Undefined subroutine &main::sub MySub{  print  "hello from a sub in a variable!";   } called at test.p line 8.

Again, I can't write it to disk and then use Require.
Thanks for any help!
0
Comment
Question by:jgore
3 Comments
 
LVL 1

Expert Comment

by:baltman
ID: 6989897
I don't think it is possible. A subroutine needs to be defined somewhere before it can be executed.

Why would you want to do this? Is the subroutine always different? Can't you just put the subroutine in the script with lots of variables which you can change without saving anything on a disk? Maybe you could give some more details?

Again, variables can be placed in a subroutine, not the other way around. The subroutine needs to exist before it is executed....

BA
0
 
LVL 84

Accepted Solution

by:
ozo earned 250 total points
ID: 6989930
my $routine = sub {  print "hello from a sub in a variable!";   };    

&$routine;
0
 

Author Comment

by:jgore
ID: 6989944
This is more what I meant (This Works):

my $routine = "sub MySub{  print  \"hello from a sub in a variable!\";   }";
my ($routinename)=($routine =~ m/sub (.*?)\{/);
eval $routine;
&$routinename;

This way you can load routines into variables with nothing
being hard-coded. You could even make routines on-the-fly!
Can we say "A I ?" ;-)
I really just wanted a way to load perl code from a
text config file in which the code may be changed depending
on a seperate program (a Visual Basic config program). Now
my perl program can load perl code from a config file
and run it without having to know in advance anything
about the code (nothing hard-coded).
In any case, thanks everyone!
0

Featured Post

Efficient way to get backups off site to Azure

This user guide provides instructions on how to deploy and configure both a StoneFly Scale Out NAS Enterprise Cloud Drive virtual machine and Veeam Cloud Connect in the Microsoft Azure Cloud.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
perl search and replace 6 168
Question about @INC variable in perl 1 59
Is it true to say that Python is successor of Perl? 7 179
Perl tar error 8 66
I've just discovered very important differences between Windows an Unix formats in Perl,at least 5.xx.. MOST IMPORTANT: Use Unix file format while saving Your script. otherwise it will have ^M s or smth likely weird in the EOL, Then DO NOT use m…
A year or so back I was asked to have a play with MongoDB; within half an hour I had downloaded (http://www.mongodb.org/downloads),  installed and started the daemon, and had a console window open. After an hour or two of playing at the command …
Explain concepts important to validation of email addresses with regular expressions. Applies to most languages/tools that uses regular expressions. Consider email address RFCs: Look at HTML5 form input element (with type=email) regex pattern: T…

831 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question