Solved

How to call a Perl subroutine from C and Java?

Posted on 2007-11-15
12
668 Views
Last Modified: 2012-08-13
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 JAVA and C, getting the return value back in both cases?

Any suggestions?  Thanks in advance.
0
Comment
Question by:Kushal_Agarwal
  • 3
  • 2
  • 2
  • +3
12 Comments
 
LVL 48

Expert Comment

by:Tintin
ID: 20291814
You still haven't given a good reason as to why you can't have a Perl script wrapper or why you need this subroutine in a package.  It would certainly make your life a lot easier.
0
 
LVL 86

Expert Comment

by:CEHJ
ID: 20291915
You can always invoke the perl interpreter using Runtime.exec. See http://www.javaworld.com/javaworld/jw-12-2000/jw-1229-traps.html
0
 

Author Comment

by:Kushal_Agarwal
ID: 20292052
What do you mean by a perl script wrapper?
I don't care if this subrouting is in a package or not, as long as I can invoke it from Shell scripts, Java and C, getting the return value in each case.
0
ScreenConnect 6.0 Free Trial

Discover new time-saving features in one game-changing release, ScreenConnect 6.0, based on partner feedback. New features include a redesigned UI, app configurations and chat acknowledgement to improve customer engagement!

 
LVL 48

Accepted Solution

by:
Tintin earned 63 total points
ID: 20292552
In that case, you can make life *so* much easier, by changing it to:

#!/usr/bin/perl
my $string = shift;
# decrypt code here
print $decrypt;

Then in your shell script, Java and C programs, you simply call the perl script, eg:

In shell

decrypt=`/path/to/script.pl ABC`

In C/Java, just use the equivalent call.

0
 
LVL 84

Assisted Solution

by:ozo
ozo earned 63 total points
ID: 20292905
#include <stdio.h>
main(){
  char value[100];
  FILE *P = popen("perl -Mscript -e 'print crypto::decrypt'","r");
  fgets(value,100,P);
  pclose(P);
  printf("value=%s\n",value);
}
0
 
LVL 40

Assisted Solution

by:evilrix
evilrix earned 62 total points
ID: 20292955
0
 
LVL 92

Assisted Solution

by:objects
objects earned 62 total points
ID: 20293231

Process p = Runtime.getRuntime().exec(new String[] {"/usr/bin/perl", "scriptname.pl" });
// or if you don;t use a wrapper something like:
// = Runtime.getRuntime().exec(new String[] {"/usr/bin/perl","-Mscript","-e", "'print crypto::decrypt'"});
p.waitFor();
int returnCode = p.exitValue();
0
 

Author Comment

by:Kushal_Agarwal
ID: 20294434
for the returnCode, would it be able to return a string value as well?
0
 
LVL 48

Expert Comment

by:Tintin
ID: 20294516
My examples return the string value.
0
 
LVL 92

Expert Comment

by:objects
ID: 20294591
you can read output from stdout/stderr using getInputStream() and getErrorStream() methods of Process class

http://exampledepot.com/egs/java.lang/ReadFromCommand.html
0

Featured Post

PRTG Network Monitor: Intuitive Network Monitoring

Network Monitoring is essential to ensure that computer systems and network devices are running. Use PRTG to monitor LANs, servers, websites, applications and devices, bandwidth, virtual environments, remote systems, IoT, and many more. PRTG is easy to set up & use.

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…
Examines three attack vectors, specifically, the different types of malware used in malicious attacks, web application attacks, and finally, network based attacks.  Concludes by examining the means of securing and protecting critical systems and inf…
Video by: Grant
The goal of this video is to provide viewers with basic examples to understand and use for-loops in the C programming language.
This tutorial will introduce the viewer to VisualVM for the Java platform application. This video explains an example program and covers the Overview, Monitor, and Heap Dump tabs.

773 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