How to read and write to an external program using Perl ?

[bosna72]

Hi

There is en htpasswd.exe file used by apache server located in Bin directory. This file is used in order to handle different login functions on the server. I have tried to communicate with this exe using my perl script that looks like this:

#!C:\Perl\bin\perl.exe
# funktion.pl
use strict;
use warnings;
use IO::Handle;
use File::Spec;
use CPAN;

use Win32::Registry;

system ('C:\Perl\eg\htpasswd.exe -b logg user passwd'); #this one works but i would like to be more flexible and do it like this:


$str = 'C:\Perl\eg\htpasswd.exe -b logg user passwd';
system ($str);
#this one doesn't work, WHY ?

Is there any other (better) way of opening, reading and writing to an external program using Perl.

Thanks

[avenger]

use IO::Handle;
use File::Spec;
use CPAN;
use Win32::Registry;

You do not need to use any of those modules.

system ('C:\Perl\eg\htpasswd.exe -b logg user passwd'); #this one works but i would like to be more flexible and do it like this:

$str = 'C:\Perl\eg\htpasswd.exe -b logg user passwd';
system ($str);
#this one doesn't work, WHY ?

There is no difference between the two. However, the better way to do it would be along the lines of

$program = 'C:\\Perl\\eg\\passwd.exe'; # there's not a difference between '\b' and '\\b', but there is a difference between '\\' and '\'
@params = qw/-b logg user password/;
system ($program, @params);

This is more efficient because it does not require perl to pass the command to a command interpreter (cmd).


If you get an error along the lines of

Global symbol "$str" requires explicit package name at funktion.pl line 15.
Execution of funktion.pl aborted due to compilation errors.

this is because you are 'use'ing strict vars (this is good). Define $str like 'my $str = ...' instead.