What characters can cause "The request line contained invalid characters following the protocol string." message to appear?

Question

When using PHP file_get_contents(), What characters will cause the following error to appear: "The request line contained invalid characters following the protocol string."

Here's my URL: http://MySite.com/File.php?dummy=235&data1=103.019|103.019|99.973|98.086|100|105.584|94.499|91.76|74.257|65.862|63.528&data2=103.019|103.019|99.973|98.086|100|105.584|94.499|91.76|74.257|65.862|63.528&data3=103.019|103.019|99.973|98.086|100|105.584|94.499|91.76|74.257|65.862|63.528&data4=103.019|103.019|99.973|98.086|100|105.584|94.499|91.76|74.257|65.862|63.528&data5=103.019|103.019|99.973|98.086|100|105.584|94.499|91.76|74.257|65.862|63.528&data6=103.019|103.019|99.973|98.086|100|105.584|94.499|91.76|74.257|65.862|63.528&Label1=Inland Empire (MSA) Actual (03-23-10)&Label2=Inland Empire (MSA) Forecast (03-23-10)&Label3=Inland Empire (MSA) Actual (03-23-10)&Label4=Inland Empire (MSA) Forecast (03-23-10)&Label5=&Label6=&Title=Apartment Prices&Label=Q4-2006&IndexDate=Q4-2007&YaxisLabel=&Subtitle=&Smooth=&LineBar=&EndDate=0&HalfWidth=GetYAxis=Yes

It doesn't work even if I URL encode

Answer 1

This will depend on what protocol you're using. Based on the error and common usage, I'll assume you're attempting to fetch a remote file using a URL as the parameter. RFC-1738 has the details on how URLs are supposed to be encoded, but the short answer is pretty much all non-alphanumeric characters except-_. Note that some other symbols such as % aren't invalid per se and won't cause an error, but unless they are encoded they may not transmit properly.

You'll want to use urlencode() on whatever URL you're attempting to fetch.