| Re: Pipe the content of a variable to a process [message #173024 is a reply to message #173021] |
Fri, 18 March 2011 02:30   |
Jerry Stuckle
Messages: 2598
Registered: September 2010
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Senior Member |
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On 3/17/2011 5:35 PM, Marco wrote:
> On 2011-03-17 Marco<netuse(at)lavabit(dot)com> wrote:
>
>> Hi,
>>
>> how can I pipe the content of a variable into a process' standard input and
>> save its output into another variable?
>> [...]
>
> I made some progress. But I still have problems. In the following example I
> can use »cat« as process without problems. But gnuplot produces no output, but
> a return value of zero, that means it's successfull. But where's the output?
>
> When I call gnuplot with the »passthru« command it works as expected that
> means that it is in the PATH and produces output on stdout with the given
> input. What's the problem here?
>
> <?php
> $stdin_data = 'set terminal svg;plot sin(x)';
>
> $descriptorspec = array(
> 0 => array( 'pipe', 'r' ), // stdin to read from
> 1 => array( 'pipe', 'w' ), // stdout to write to
> 2 => array( 'pipe', 'a' ), // stderr
> );
>
> // This works
> // $process = proc_open( 'cat', $descriptorspec, $pipes );
>
> // This doesn't produce output
> $process = proc_open( 'gnuplot', $descriptorspec, $pipes );
>
> if ( is_resource( $process ) ) {
> fwrite( $pipes[0], $stdin_data );
> fclose( $pipes[0] );
> $content = stream_get_contents( $pipes[1] );
> fclose( $pipes[1] );
> fclose( $pipes[2] );
>
> $return_value = proc_close( $process );
>
> // cat and gnuplot return 0
> echo $return_value . "\n";
> echo $content;
>
> // This works
> // passthru( "gnuplot -e '$stdin_data'" );
> }
> ?>
>
>
> Marco
>
What's in stderr? What happens if you write stdout and stderr to a file
(for testing)?
--
==================
Remove the "x" from my email address
Jerry Stuckle
JDS Computer Training Corp.
jstucklex(at)attglobal(dot)net
==================
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