将php变量传递给使用shflags的bash脚本

Question

I am trying to make a PHP program triggered by a web submit tell a bash script to run with a single command line parameter. I am using the shflags command line parser for bash.

The pertinent part of the PHP script is as follows:

// generate unique filename
    $destinationFolder = Mage::getBaseDir('media') . DS . 'webforms' . DS . 'xml';
    $filename = $destinationFolder . DS . $result->getId().'.xml';


    // create folder
    if (!(@is_dir($destinationFolder) || @mkdir($destinationFolder, 0777, true))) {
        throw new Exception("Unable to create directory '{$destinationFolder}'.");
    }

    // export to file
    $xmlObject->getNode()->asNiceXml($filename);

    // define parameters to pass

    exec ( '/opt/bitnami/apache2/htdocs/sfb/scripts/xform.sh --xmlfile'.' '.$filename);      

}

}
?>

The bash script (xform.sh) (just a test script) is as follows.

#!/bin/bash
. ./shflags

echo "foo" >> /opt/bitnami/apache2/htdocs/sfb/scripts/seeds/xform/$$".txt"
echo "foo" >> /opt/bitnami/apache2/htdocs/sfb/scripts/seeds/xform/foo.txt

DEFINE_string 'xmlfilename' 'test' 'filename of current x.xml file from webforms' 'Z'


FLAGS "$@" || exit 1
eval set -- "${FLAGS_argv}"

echo "xml file was" ${FLAGS_xmlfilename} >> /opt/bitnami/apache2/htdocs/sfb/scripts/seeds/xform/foo.txt

The bash script works correctly from the command line, i.e.

$xform.sh --xmlfilename 1.xml

writes "xml file was 1.xml" to the foo.txt file.

When the PHP script is triggered from the web, the first part works correctly, i.e. it writes "foo" to the two target files, foo.txt and $$.txt. However, the xmlfilename variable is not coming along, and I really need that file name to be passed to the command line! (Note I should not need to use escapeshellarg because the file name is generated by my PHP program, not by user input.)

I have checked all the file permissions I can think of. xform.sh and shflags are both members of the www-data (Apache) group, owned by Apache, and a+x.

My suspicions are that the problem is related either to a) my PHP exec syntax or b) file permissions. Everything works as intended except the bit after xform.sh in this line!

exec ( '/opt/bitnami/apache2/htdocs/sfb/scripts/xform.sh --xmlfile'.' '.$filename); 

UPDATE:

I've narrowed the problem some more by isolating the problem with some test code. With:

$script="echo";
$xmlfilename="$filename";
$target=">> /opt/bitnami/apache2/htdocs/sfb/scripts/seeds/xform/foo.txt";

exec ("$script $xmlfilename $target");   

...

PHP correctly writes the $filename to foo.txt, so $script works when value is "echo" and $filename works too.

When I set $script to a different simple form of the xform script that (only) writes the data to the file, that also works correctly.

So the problem is specifically with something that happen when PHP tries to write the $filename as a command line variable. Does a script run by Apache need more permissions than usual if it includes a command line variable?

Sigh.

Answer 1

In your exec() call you have the flag as --xmlfile but you are calling it from the command line as --xmlfilename