PHP output file header exception

PHP output file header error local nginx1.09 test everything is normal, upload to the server nginx1.12, when selecting text output, the complete code is returned: PHPcode & lt ;? Php @ $ id]? $ _ GET [id]: a; @ $ txt $ _ GET [txt]? $ _ GET [txt]:; $ treesarr PHP output file header error
The local nginx 1.09 test is normal. upload the file to nginx 1.12 on the server and select Text outputError reported
Complete code:

PHP code

Demo address: http://guilyn.host.org/cn/demo/full.php

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This should be the reason for the BOM header. You can modify php. ini output_buffering = On or remove it.
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When saving it as utf8, you need to pay attention to this header...
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Int_set ('output _ buffering = on'); I don't know if I wrote the error?