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

I'm running a script in Unix, after every line that print's I need to simulate <ENTER>, I read in unix this is \n.

So for example I type "perl script.pl" which executes this script. So the first command that the script runs is "execopu -text". Then I get a prompt for more data and then I need to script to feed "cell" to the program, and so on for the rest of the "print's" that I do to the screen.

Right now the script just prints all the text to the screen and nothing executes. 
#!/usr/bin/perl

my @sitenumbers = (7,12);

print "execopu -text\n";
print "cell\n";

foreach my $site_number (@sitenumbers){

print <<EOF;
u
csno = $site_number
ccuoosmin_3g1x = ""
ccuoos_3g1x = ""
u
EOF
}

[download]
The screen should read like this
>perl script.pl
>execopu -text                   #This comes from my script

Enter form name:  cell           #The computer asks for the form name 
+and the script populates it with "cell" and then <ENTER>

Enter Operation: u               #The computer asks for "Operation" an
+d the script populates it with "u" and and then <Enter>
Enter Value: csno = $site_number

[download]
And this should continue for the rest of the script.

Replies are listed 'Best First'.
Re: Auto Feeding Data to Unix Programs
by wazoox (Prior) on Apr 19, 2005 at 22:36 UTC

    You need two different things : first grab output from the external program, secondly feed it with your response. That's exactly what IPC::Open2 is for.

    Search this site for examples using Open2, they abound.

    If you want a more complex interaction, perhaps should you look at Expect instead... YMMV.

[reply]
Re: Auto Feeding Data to Unix Programs
by fauria (Deacon) on Apr 19, 2005 at 22:53 UTC
    If you want to fill values automaticallly as they prompt, you can use Expect module for Perl.
[reply]
Re: Auto Feeding Data to Unix Programs
by ikegami (Patriarch) on Apr 19, 2005 at 22:32 UTC

    Are you trying to send text to the execopu program? If so, check out Perl's open(FH, '|...') function:

    #!/usr/bin/perl

open(EXECOPU, '| execopu -text')
or die("Can't run execopu: $!\n");

my @site_numbers = (7, 12);

print EXECOPU "cell\n";

foreach my $site_number (@site_numbers) {
   print EXECOPU <<"EOF";
u
csno = $site_number
ccuoosmin_3g1x = ""
ccuoos_3g1x = ""
u
EOF
}

    [download]

    You might also want to check our IPC::Open2, IPC::Open3 and IPC::Run, especially if you want to capture the output.

[reply]
[d/l]
[select]
      Yes, I am trying to send all that text to the "execopu" program. It keeps on prompting me for input and I need to feed it automatically.
[reply]
      When I feed "u" to the script I get this error:

      FD00 - Cannot convert ODIN stringwad to subschema. Check for a null field and/or verify the RC/V product and mask are compatible.

      Any idea if a null field is getting fed?
[reply]
[d/l]
        What's a null field? I'm not familiar with execopu, so you'll have to give us more info. I think you might need to remove the "u" at the bottom of the heredoc (i.e. I think you might need to delete the second line with the "u", right before the EOF).
[reply]

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