?
Solved

How to invoke a perl function from a shell sciprt and C code, and get a string back as the return value?

Posted on 2007-11-14
7
Medium Priority
?
825 Views
Last Modified: 2010-05-18
Hi,

I have a perl script in the following format.  It defines a package crypto, and has function decrypt.

package crypto;

sub decrypt
{
   ...
   my retval = "String";
   return retval;
}

Decrypt, returns the plain_text string of whatever it was told to decrypt.

Now, my problem is that how can I call this function from a Shell script and C code, getting the return value back in both cases?

Any suggestions?  Thanks in advance.
0
Comment
Question by:Kushal_Agarwal
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
7 Comments
 
LVL 48

Accepted Solution

by:
Tintin earned 750 total points
ID: 20285590
From a shell script:

string=`perl -Mcrypto -e 'print crypto::decrypt("abc")'`

But why don't you just have a calling Perl script that takes the args?
0
 
LVL 48

Expert Comment

by:Tintin
ID: 20285594
eg:

#!/usr/bin/perl
use crypto;
my $string = shift;
print crypto::decrypt($string);
0
 
LVL 84

Expert Comment

by:ozo
ID: 20285614
#!/bin/sh
cat <<'END' > script.pm
package crypto;

sub decrypt
{my $retval = "String";
   return $retval;
}
1;
END
value=`perl -Mscript -e 'print crypto::decrypt'`
echo $value
0
Industry Leaders: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

 

Author Comment

by:Kushal_Agarwal
ID: 20289245
Tintin,
I thought about that, but the problem is that its other people who have the shell scripts, and they are not too excited about changing them to perl scripts.

Now when I invoke the function from the shell script like you mentioned, how do the parameters get passed, meaning are they going to be visible in the process tree?
0
 

Author Comment

by:Kushal_Agarwal
ID: 20289251
Also, how can I do the same thing from C code?
0
 

Author Comment

by:Kushal_Agarwal
ID: 20289281
Ozo,

To call the perl function decrypt, don't I just need the line
value=`perl -Mscript -e 'print crypto::decrypt'`

What is everything above it for?
0
 
LVL 51

Expert Comment

by:ahoffmann
ID: 20291001
> .. re they going to be visible in the process tree?
yes (at least for the examples as shown above)
0

Featured Post

On Demand Webinar - Networking for the Cloud Era

This webinar discusses:
-Common barriers companies experience when moving to the cloud
-How SD-WAN changes the way we look at networks
-Best practices customers should employ moving forward with cloud migration
-What happens behind the scenes of SteelConnect’s one-click button

Question has a verified solution.

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

Summary: This tutorial covers some basics of pointer, pointer arithmetic and function pointer. What is a pointer: A pointer is a variable which holds an address. This address might be address of another variable/address of devices/address of fu…
This is a short and sweet, but (hopefully) to the point article. There seems to be some fundamental misunderstanding about the function prototype for the "main" function in C and C++, more specifically what type this function should return. I see so…
The goal of this video is to provide viewers with basic examples to understand recursion in the C programming language.
The goal of this video is to provide viewers with basic examples to understand how to use strings and some functions related to them in the C programming language.
Suggested Courses

777 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