Pass input to a C program and get output using php - php

I am working on a project and I wrote two C programs that convert date and time into minutes and then back. What I want to do is pass a php variable into a C program and then have the C program return the result to a variable in php.
I realize that you can use popen or exec commands but I am unsure how to use these commands.
How would I structure the php code?
What input and output commands would I have to use in the C program? If you guys could give me a few examples that would be great. I learn better from examples.
Thanks in advance.

$cmd = "/path/to/prog " . escapeshellarg($something);
$c_output = shell_exec($cmd);

Related

Python PHP equivalent

I have been using PHP for a while now with my Apache2 web server on my raspberry pi. It works great, but I get tired of always having to think "how do I X in PHP" or "what was the function name for this in PHP".
I am under the strong impression that there should be something equivalent in which I can replace the <?php ?> code with python code, but my search results have been confusing at best.
I am essentially looking for something where I can write whatever python code I want in an HTML script and have it interpreted and executed and its output inserted into the page when it is requested.
For example, to make a table of users from a list in python.
<table><tr><td>User list</td></tr>
<?python
import json
library=json.load(open(some_json_file,'r'));
for user in library:
print "<tr><td>"+user+"</td></tr>"
?>
</table>
I'm under the impression that chameleon can do this with its code blocks as described here,(https://chameleon.readthedocs.io/en/latest/reference.html) but as I look deeper, I get the impression it doesn't work like I am thinking it should. This is the impression I have gotten from all of the template engines I have looked at, as well as WSGI
Are there good drop in python alternatives for PHP? Or are there ways to cleanly wrap semi complex python code into my php in way that doesn't involve writing an additional python script that is called by PHP? I've tried exec() with python -c; but this was less than ideal having to escape all the ' and " characters...
update
The below code works just fine, but can become very slow if run multiple times in a script (takes about 0.4 seconds each time on a raspberry pi3). I have written a program in python that runs in the background and handles requests from php, and runs about 15x faster. I'm now maintaining it here on github.
Original Answer
After messing around I was able to come up with something mostly suitable for what I am trying to do. Inside my php I create a function that executes python scripts.
<?php
function py($s){
exec("python -c '$s'",$arr);
foreach($arr as $v){
echo $v."\n";}
}
?>
Then I use php Heredoc(equivalent to python """ , means I don't have to escape every single double quote) to fill the function:
<?php
py(<<<python
print "Hello world<br>"
s="ello world"
for x in s:
print x+"<br>"
python
);
?>
outputs >>>
Hello world
e
l
l
o
w
o
r
l
d
the only real downside I am experiencing at this point is that this method precludes me from using single quotes anywhere in my python script... :(. I'll get over it.
EDIT
I added a few more tweaks to make this even more useful. The new function is below:
<?php
function py($s,$return=false){
$s=str_replace("'","'\''",$s);
$h=<<<head
def cleanup():
for x in globals().keys():
if not x.startswith("_"):
del globals()[x]
import dill
try:
dill.load_session("pyworking.pkl")
except:
pass
head;
$f=<<<foot
import dill
dill.dump_session("pyworking.pkl")
foot;
if ($return==false){
echo shell_exec("python -c '$h$s$f'");
}
else {
return shell_exec("python -c '$h$s$f'");
}
}
?>
this allows you to use single quotes in the script and invoke the py() function multiple times in the same script and your variables and modules will follow you. At the end of the script you just call the clean up (or using php clear the pyworking.pkl file) and wipe the environment clean.
I also put this function in a file and in my pyp.ini I used the auto_prepend_file=my/file/location to automatically include it, so no need to load it before hand.
Overall I am very happy with this method, especially since I can read php variables inside my python script. Passing objects is as simple as:
<?php
$data_en=json_encode($data);
py(<<<p
import json
data=$data_en
#do something with data
p
);
?>
this would be perfect if I could think of a way to assign values to php variables inside the script, but its not a bad workaround if you want a fusion of php and python or just a way to do everything in python without writing a python webserver (which i have also done).

Output from a PHP script to C scanf of program

I wonder how is it possible to pass an output from PHP to scanf of a c program? The normal way of inputing in this C program is to use an echo -ne "\x0a etc..........." | ./program on terminal. The thing is that I cannot apply it on PHP. could someone help me? Lets say I want to output the variable $var from PHP to the C program.
Use popen() inside the script to run a command with input from the script. To get hex characters, put them inside a double-quoted string, and concatenate them to the variables.
$pipe = popen($program, "w");
$vartmp = $passwordHEX . "\x00\x00\x00\x00\x00\x00\x00\x00‌\x00\x00x00" . $Pass‌​wordHash;
fwrite($pipe, $vartmp);
pclose($pipe);

PHP + Python - use PHP to pass string to Python program, and parse output

I have a great Python program on my webserver, which I want to use from inside my PHP web app.
Here's an example of the python command, and output as you would see it in terminal:
>>> print MBSP.parse('I ate pizza with a fork.')
I/PRP/I-NP/O/NP-SBJ-1/O/i
ate/VBD/I-VP/O/VP-1/A1/eat
pizza/NN/I-NP/O/NP-OBJ-1/O/pizza
with/IN/I-PP/B-PNP/O/P1/with
a/DT/I-NP/I-PNP/O/P1/a
fork/NN/I-NP/I-PNP/O/P1/fork ././O/O/O/O/.
You might recognize this as a typical POS tagger.
In any case, I'm confused about how to use a PHP-based web app to send this program a string like "I ate pizza with a fork", and somehow get the response back in a way that can be further parsed in PHP.
The idea is to use PHP to pass this text to the Python program, and then grab the response to be parsed by PHP by selecting certain types of words.
It seems like in PHP the usual suspects are popen() and proc_open(), but popen() is only for sending, or receiving information - not both? Is popen() able to give me access to this output (above) that I'm getting from the Python program? Or is there a better method? What about curl?
Here are all my options in terms of functions in PHP:
http://us.php.net/manual/en/function.proc-open.php
I'm lost on this, so thanks for your wise words of wisdom!
I use exec() for this purpose.
exec($command, $output);
print_r($output);
If you want to get a little heavier / fancier... give your python script an http (or xmlrpc) front end, and call that with a GET/POST. Might not be worth all that machinery though!
You could use popen(), and pass the input to your Python script as a command line argument, then read the output from the file descriptor popen gives you, or proc_open() if you want to interact bi-directionally with the Python script.
Example 1 in the proc_open manual: http://us.php.net/manual/en/function.proc-open.php gives an example of this.
If your Python needs it as stdin, you could try popening a command line:
echo "I ate pizza!"|my_python_progam.py
and just read the output. As usual, do proper input validation before sending it to the command-line.
Something like this would work
$command = '/usr/bin/python2.7 /home/a4337/Desktop/script.py'
$pid = popen('$command',r)
........
........
.........
pclose($pid)

PHP Exec command - How to pass input to a series of questions

I have a program on my linux server that asks the same series of questions each time it executes and then provides several lines of output. My goal is to automate the input and output with a php script.
The program is not designed to accept input on the command line. Instead, the program asks question 1 and waits for an answer from the keyboard, then the program asks question 2 and waits for an answer from the keyboard, etc.
I know how to capture the output in an array by writing:
$out = array();
exec("my/path/program",$out);
But how do I handle the input?
Assume the program asks 3 questions and valid answers are: left 120 n
What is the easiest way using php to pass that input to the program?
Can I do it somehow on the exec line?
I’m not a php noob but simply have never needed to do this before.
Alas, my googling is going in circles.
First up, just to let you know that you're trying to reinvent the wheel. What you're really looking for is expect(1), which is a command-line utility intended to do exactly what you want without involving PHP.
However, if you really want to write your own PHP code you need to use proc_open. Here are some good code examples on reading from STDOUT and writing to STDIN of the child process using proc_open:
http://www.php.net/manual/en/function.proc-open.php#79665
How to pass variables as stdin into command line from PHP
http://camposer-techie.blogspot.com/2010/08/ejecutando-comandos-sobre-un-programa.html (this one is in Spanish, sorry, but the code is good)
Finally, there is also an Expect PECL module for PHP.
Hope this helps.
Just add the arguments to the exec line.
exec("/path/to/programname $arg1 $arg2 $arg3");
... but don't forget to apply escapeshellarg() on every argument! Otherwise, you're vulnerable to injected malicious code.
$out = array();
//add elements/parameters/input to array
string $execpath = "my/path/program ";
foreach($out as $parameter) {
$execpath += $parameter;
//$execpath += "-"+$execpath; use this if you need to add a '-' in front of your parameters.
}
exec($execpath);

want to run c program from php using exec() function

i'm trying to run one c executable file using php exec().
When c contains a simple program like print hello. I'm using
exec('./print.out')
It's working fine. But when I need to pass a argument to my c program I'm using
exec('./arugment.out -n 1234')
It is not working. Can any body tell me how to pass arugment using exec to c program.
From taking a look at the php documentation, it appears that exec treats arguments a bit oddly. You could try doing
exec("./argument.out '-n 1234'")
to prevent it from mangling them (it normally separates them all on space, which might be what's messing it up).

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