Passing variable to C prog from PHP

vypergal

Hi.

I have created a form whereby users can input some values into a form. From this form in the PHP file, I would like to pass the input values into a C program.

I am quite confused as to which function I should be using (exec, system, ??). I think I should be using exec since I am passing some values into the C program but I can't find the correct syntax that I should be using.

I also need to read out some values from the C program and display it on my browser.

Could some please help me???

Thanks in advanced.

gregor63

Just write and read to/from text file, in PHP script and C program.

Gregor63

vypergal

Hi. Thanks for the reply.
I tried implementing the reading and writing of the variables in the file but when I use a fopen(), i seem to get a permission error. I tried to enable the directory permission in the Apache "httpd.conf" with the following command
<Directory /path/to/dir>
Option FollowSymlink
Override All
</Directory>
and restarted my Apache server. I still am faced with the permission error problem. Am I doing something wrong here?

Another question is this. With the implementation that was suggested, won't there be a lot of files created? Would this overload the server? 😕

Thanks in advanced.

gregor63

when I use a fopen(), i seem to get a permission error.

Apache after starting gives the user such permision as has the user named "nobody" (or other if you changed default value in http.conf). So, files created by PHP scripts are scripts of the user called "nobody". If C programs want to get access to these files they have to be run by "nobody".

With the implementation that was suggested, won't there be a lot of files created? Would this overload the server?

I suggested one or a few text files with data, common for PHP scripts and C program. So, it is not a problem with overloading the server. The real problem is when PHP script write to the text file and C program wants to read. It is a problem with semaphores - fork function and so on. Read something about it and try to find good scripts written by others. There in no sense to invent a wheel :-)

Good luck

Gregor63

gregor63

For tests with the common text file you can just run C program started not from command line but started via browser as CGI program - permisions given by apache to CGI programs and PHP scripts are the same.

It should work until CGI program and PHP script want to take access to the shared file in the same time.
If you want it works OK in all conditions, you should include mechanisms of locking access to the file or use any database where solving of this problem is implemented.

Gregor63