How to pass a variable from php to a running perl script

Question

I have a perl script that has an endless loop that reads an integer from the user and add it to the variable $b every time;

$b = 0;
while ( 1 == 1 ) {
    $a = <STDIN>;
    $b = $b + $a;
    print $b + "\n";
}

I have a php form that has an input-text field and submit button, and when pressing the submit button I want to pass the value given in the input-text field to the running perl script and get the last value of the $b variable to show it in my php form.

So my question is how to do this interconnection between php and perl?

yes I tried but I couldn't keep calling the same running script — VFX, May 06 '17 at 13:00
Do you control the Perl program? Can you make it listen on a socket? Or something else, like listening on TCP. — simbabque, May 06 '17 at 21:07
Youhave three valid answers now. I suggest you read [*What should I do when someone answers my question?*](http://stackoverflow.com/help/someone-answers) — Borodin, May 07 '17 at 09:01
what's the status of this question, is it solved by any answer below? if so, the question should be marked as solved @VFX — Funk Forty Niner, May 10 '17 at 15:16

score 0 · Answer 1 · answered May 06 '17 at 13:10

0

You can open a pipe to a new instance of your Perl program with popen

$pipe = popen("/path/to/program.pl", "w");

then you can write your numbers to the pipe and the Perl code will add then up

fwrite($pipe, "99\n");

answered May 06 '17 at 13:10

Borodin

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how do I get the value of $b back to php using the $pipe ? – VFX May 06 '17 at 13:15
@VFX: That is a different problem and you need to open a new question. The `$pipe` connects to the Perl program's stdin, so you can't read from it. You will need to use `proc_open` instead. Why do you need a Perl program to add numbers up for your PHP code? – Borodin May 06 '17 at 13:19
Actually, I don't need a Perl script to add numbers up, but this example is simple to ask my question, the main idea is the interconnection between php and perl – VFX May 06 '17 at 13:25

score 0 · Answer 2 · answered May 07 '17 at 08:35

0

Both perl and php can do IPC via UNIX sockets, message queues and FIFO and much more. Connecting to an already running process STDIN - if it exists and is a named device/object - is not so easy.

answered May 07 '17 at 08:35

ulix

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How to pass a variable from php to a running perl script

2 Answers2