Uploading shapefile to PostGIS database using PHP

I want to insert a s://forum.tuteehub.com/tag/h">href="s://forum.tuteehub.com/tag/h">https://forum.tutees://forum.tuteehub.com/tag/h">hub.com/tag/ss://forum.tuteehub.com/tag/h">hapefile">ss://forum.tuteehub.com/tag/h">hapefile into a PostGIS s://forum.tuteehub.com/tag/d">database using PHP. I go ts://forum.tuteehub.com/tag/h">hrougs://forum.tuteehub.com/tag/h">h ts://forum.tuteehub.com/tag/h">he examples ans://forum.tuteehub.com/tag/d">d I tries://forum.tuteehub.com/tag/d">d ts://forum.tuteehub.com/tag/h">he following:

$commans://forum.tuteehub.com/tag/d">d = 'ss://forum.tuteehub.com/tag/h">hp2pgsql -s 2100 -s://forum.tuteehub.com/tag/d">d /D:\CHECK DATA-group\2016\Ayomi\JULY\12FCP151Sup88Ss://forum.tuteehub.com/tag/h">h99\121800151s00088s0099\CM121800151s00088s0099Poly.ss://forum.tuteehub.com/tag/h">hp | psql -s://forum.tuteehub.com/tag/h">h locals://forum.tuteehub.com/tag/h">host -p 5432 -s://forum.tuteehub.com/tag/d">d sss://forum.tuteehub.com/tag/h">h -U postgres';

But it is not working. Then in the forum, I saw an instruction to add the exec($commans://forum.tuteehub.com/tag/d">d,$out,$ret); to the above code. Can any one explain me what is meant by $out,$ret variables?