convert rtf to html through abiword

[krrr25]

I am trying to convert a rtf file to html file in php. The below code is not working, not giving any error also.

<?php
$handle = popen("/usr/bin/abiword --plugin AbiCommand 2>&1", "w");
fputs($handle, "server");
fputs($handle, "load /var/www/abiword/test.rtf");
fputs($handle, "save /var/www/abiword/test.html");
?>

when i do this conversion through terminal with the below command, its working fine and converting.
abiword --to=rtftohtml.html test.rtf

But through php page its not converting, please suggest me the right way to convert from php page.