http://www.perlmonks.org?node_id=1005013

tmurnane has asked for the wisdom of the Perl Monks concerning the following question:

I have a setup file that has to be run silently like:

./setup < answerFile >> logfile

Where answerFile is basically has the input to the setup:

1 /path/to/install Company Name etc...

Is there a way in perl to open the command for input and print the answers to each question?

my $setup = "./setup"; my $answerFile = "./AnswerFile"; my $logFile = "./log"; open (IN, "<$answerFile") || die "can't open $answerFile: $!"; my @answerFile = <IN>; close IN; my $i=0; open (SETUP, "| $setup") || die "can't run $setup: $!"; while(<SETUP>) { # stuff gets printed out then a question is displayed # want to answer the question from $answerFile # perhaps: print SETUP $answerFile[$i++]; } close SETUP;

Running the setup without the answerFile produces something lilke:

================================================================= foo Server Installation, build spf-14-3-0_12326 ================================================================= WARNING: NIS Detected. Please ensure that the services entry uses files, otherwise this installation of foo Server Installation may no +t function correctly. WARNING: sudo is not installed or not on path. foo Loader will not be able to login as anyone other than the current user. Checking for existing installations... Please choose from one of the options listed below. 1. New Installation (default) 2. Upgrade /tril21/workarea/12/server 3. Upgrade /tril21/workarea/13.5/server Enter choice (1-3): $answerFile[0] Please enter the name of your organization: $answerFile[1] Where would you like to install foo Server? : $answerFile[2]

Is this even possible to do like this?

Currently - I'm just running a system on the command like so:

system ("$setup < $answerFile");

Which I do not think is ideal

Any guidance would be very appreciated.

Replies are listed 'Best First'.
Re: open command for input
by aitap (Curate) on Nov 21, 2012 at 21:35 UTC
    Have a look on IPC::Run - it might do just what you need to do.
    Sorry if my advice was wrong.

      Thanks...this looks exactly like what I need, however, I do not have that module on my system and I would need to go through system support to it - I know I can install it without sys admin but this script is to go to clients servers and this would be a difficult task to ask of clients to install this module.

      If this is my only option, I do have ActiveState's Perl Dev Kit which allows me to build individual executables for the 5 platforms we support - Windows, Solaris, HP Linux, and AIX. But I believe I would have to install the Dev Kit on each of the platforms to do that.

        Another option is IPC::Open2, which is in core. This will require a bit more code, but should work:

        use IPC::Open2; open IN, "<", "commandfile"; # unfortunately, scalar filehandles won't + work this way open OUT, ">", "logfile"; my $pid = open2(">&OUT", "<&IN", "theprogram"); waitpid $pid, 0;

        You can also package your application together with module you use with the help of PAR::Packer (its installation is required only on the packager's computer). But I don't know whether it will interfere with PDK or not.

        Sorry if my advice was wrong.