Databases
StackOverflow2013
Postsdbo
POspawning a command prompt in a different process and sending/receiving commands on Windows
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POspawning a command prompt in a different process and sending/receiving commands on Windows
    primarykey
    data
    text
    <p>I have a problem at hand which requires me to spawn a command prompt as a different process and send some commands to it and capture/parse the command output. This interaction needs to be in the form of a parent-child process where say all the commands can be put in a ruby file and upon running the ruby file, the commands are sent to the console(command prompt) and output is received from it and processed in the ruby script.</p> <p>The general logic which I would follow is:</p> <ol> <li>Spawn a different process by using a fork and get a process id</li> <li>Obtain streams for the process</li> <li>Write to the input stream of the process and read from the output stream.</li> </ol> <p>The environment which I am using is Windows XP machine with Ruby 1.9.2 installed on it. I downloaded the win32-process library found over <a href="http://win32utils.rubyforge.org/" rel="nofollow">here</a>. By using that library, I could do step 1 as follows</p> <pre><code>require 'win32/process' APP_NAME = "C:\\Windows\\system32\\cmd.exe" process_info = Process.create(:app_name =&gt; APP_NAME, :creation_flags =&gt; Windows::Process::CREATE_NEW_CONSOLE, :process_inherit =&gt; false, :thread_inherit =&gt; true, :cwd =&gt; "C:\\" ) </code></pre> <p>Since the win32-process library is based on using processes and threads on windows, I tried to go through the <a href="http://msdn.microsoft.com/en-us/library/windows/desktop/ms686937%28v=vs.85%29.aspx" rel="nofollow">MSDN</a> help for it. While reading the <a href="http://msdn.microsoft.com/en-us/library/windows/desktop/ms682528%28v=vs.85%29.aspx" rel="nofollow">Creation of a Console</a> article, I found that the GetStdHandle method could be used to get the handles to the input and output streams. But, i could not find this method implemented anywhere in win32-process.</p> <p>Can someone provide me with some guidance on how to proceed with steps 2 and 3?</p> <p>Also, is there any other way which can be used to solve the problem at hand?</p> <p>Also, I would like to learn more about inter-process communication or in general spawning and forking of processes, so can somebody please tell me some good references where I could study them?</p> <p>Thanks in advance </p>
    singulars
    1. PO
      singulars
      1. PTAnswer
    1. This table or related slice is empty.
    1. PTQuestion
    1. USchaitanya
    1. USchaitanya
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POspawning a command prompt in a different process and sending/receiving commands on Windows
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. POspawning a command prompt in a different process and sending/receiving commands on Windows
      1. This table or related slice is empty.
      1. VTUpMod
    3. VO
      singulars
      1. POspawning a command prompt in a different process and sending/receiving commands on Windows
      1. This table or related slice is empty.
      1. VTUpMod
    1. COWhy can't you just use `system()` or backticks to run your commands?
      singulars
      1. POspawning a command prompt in a different process and sending/receiving commands on Windows
      1. USCasper
    2. COI think system() does not return a handle
      singulars
      1. POspawning a command prompt in a different process and sending/receiving commands on Windows
      1. USchaitanya
    3. COOk, what about `IO.popen`? Example: `IO.popen('dir').readlines`.
      singulars
      1. POspawning a command prompt in a different process and sending/receiving commands on Windows
      1. USCasper
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload