Access an executable from perl script

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

Hi There, I have a client server application in which client sends a input file to server ,server uses a tool called abc.exe on that input file, which gives an output file and sends it back to client.The name for the output file is basically output_input file.if the output file with the same name is already present then it increments the suffix at each run. I have written this code but its not working correctly.I guess there is some problem with the $abc_cmd.Can anyone tell me what I am doing wrong?


        # Read the signing image_type from the client app via the sock
+et
        $image_type = <$client_socket>;
        chop($image_type);
        
        # Setup some default filenames and command strings.
        my $unsigned_file = "unsigned.bin";
        my $signed_filename;
        my $output_file = "signed.$unsigned_file";
        my $rcv_filesize;
        my $hsm_cmd;
        my $buf;
        my $error = "ACK\n";

       $rcv_filesize = 0;                
       my $i = 1;
       while (-e $output_file) {
      $output_file = "output.$input_file$i";
                $i++;
                }
      $abc_cmd = "abc.exe" -i $input_file -o $output_file"; 
      print $client_socket "ACK\n";


    system $abc_cmd;     # Run the command
        print "DONE\n";
        
        # Open the file for reading 
         open(INFILE, $output_file) || die "ERROR:  Could not open out
+put_file for reading!\n";
        binmode INFILE;
        {
            local $/;
            $output_data = <INFILE>;
        }
        close(INFILE);

        print "$prefix Sending $output_file to the client... ";
        $client_socket->write($output_data, length($output_data));
        
        print length($output_data), " bytes: DONE\n";
        
        $client_socket->close();
        print "$prefix Socket closed, operation completed!\n";
[download]

Comment on Access an executable from perl script Download Code

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Re: Access an executable from perl script by kennethk (Abbot) on Feb 28, 2012 at 23:03 UTC
There are a few ways to run external executables from perl. The easiest, and what you probably want, is backticks: see `STRING`. For this, your command might look like: $abc_cmd = `abc.exe -i $input_file -o $output_file >null`; Other possibilities include system, open and IPC::Open3, for which you can use perlipc for reference. Update: (as per JavaFan's comment) But of course, if you redirect your output (with `>null`) or put it in some output file (with `-o $output_file`, then why would you expect to capture it? #11929 First ask yourself `How would I do this without a computer?' Then have the computer do it the same way.	[reply] [d/l] [select]
Re^2: Access an executable from perl script by JavaFan (Canon) on Feb 28, 2012 at 23:16 UTC
$abc_cmd = `abc.exe -i $input_file -o $output_file >null`; [download] I don't get this. You're redirecting the output of `abc.exe` to the file `null`, and then you want to capture the output of that. What do you expect `$abc_cmd` to be afterwards?	[reply] [d/l] [select]
Re: Access an executable from perl script by rovf (Priest) on Feb 29, 2012 at 12:05 UTC
Running the executable is done by system. But what do you mean by and return the output file ? Do you mean that you want to process the file $output_file afterwards? This is not different from processing any other file. See for instance open or IO::File. -- Ronald Fischer <ynnor@mm.st>	[reply] [d/l]