Running Perl Scripts on Linux Systems

This section provides a tutorial example on how to run Perl scripts on Linux systems. To make a Perl script file executable, you need to add '#!/usr/bin/perl' to the beginning of the script.

There are many ways to run Perl scripts on Linux:

1. Run the "perl" command with the Perl script included in the command line. For example, enter the following command line in a command window:

>perl -e "print 'Hello world!';"
Hello world!

Another example:

>perl -e "for ($i=0; $i<10; $i++) {print \"$i\n\";}"
0
1
2
3
4
5
6
7
8
9

This is a cool way to run a Perl script quickly. But you can only run scripts that are small enough to fit into one command line.

Also note that double quote (") is used to put the entire script code as one command line parameter. Any double quote inside the program needs to be protected as (\").

2. Run the "perl" command with the Perl script supplied from the standard input steam. For example, enter "perl" in a command window. Then enter the script code followed by Control-Z, which is the End Of File (EOF) indicator:

>perl
$s=0;
for ($i=0; $i<10; $i++) {
   $s+=$i;
}
print "$s\n";
^Z
45

Obviously, you can enter a much longer script in this way. But the program is not save permanently.

3. Run the "perl" command with the Perl script supplied in a file. For example, enter the following Perl script in a file called hello.prg:

   print "Hello world!\n";

Then enter the following command in a command window:

>perl hello.prg
Hello world!

This is how you normally run Perl scripts.

4. Run Perl script files as commands. You can do this, only if you insert a special line at the beginning of your script file: #!/usr/bin/perl, and assign execution permission to the script file. This special line represents the Perl installation location on the file system.

For example, enter the following script in a file called hello.pl:

#!/usr/bin/perl
   print "Hello world!\n";

Then assign execution permision and enter the script file name to run it:

>chmod a+x hello.pl
>hello.pl
Hello world!

It works!

Table of Contents

 About This Book

Perl on Linux Systems

 Perl Installation on Linux Systems

Running Perl Scripts on Linux Systems

 ActivePerl on Windows Systems

 Data Types: Values and Variables

 Expressions, Operations and Simple Statements

 User Defined Subroutines

 Perl Built-in Debugger

 Name Spaces and Perl Module Files

 Symbolic (or Soft) References

 Hard References - Addresses of Memory Objects

 Objects (or References) and Classes (or Packages)

 Typeglob and Importing Identifiers from Other Packages

 String Built-in Functions and Performance

 File Handles and Data Input/Output

 Open Files in Binary Mode

 Open Directories and Read File Names

 File System Functions and Operations

 Converting Perl Script to Executable Binary

 Using DBM Database Files

 Using MySQL Database Server

 Socket Communication Over the Internet

 XML::Simple Module - XML Parser and Generator

 XML Communication Model

 SOAP::Lite - SOAP Server-Client Communication Module

 Perl Programs as IIS Server CGI Scripts

 CGI (Common Gateway Interface)

 XML-RPC - Remote Procedure Call with XML and HTTP

 RPC::XML - Perl Implementation of XML-RPC

 Integrating Perl with Apache Web Server

 CGI.pm Module for Building Web Pages

 LWP::UserAgent and Web Site Testing

 References

 PDF Printing Version