URL encoding: how transform all HTML metacharacters (such as "<" and ">") into entities (such as "<" and ">")?

Using a ".txt" file taken from the Internet containing a time series (series of values ​​or points of a curves recorded at the time logo), construct the graph of this series us...

It's a disaster. It's all over the place and is costing me so much, not only in time, but also in opportunies and money. I have to switch webhosts. Which host is good and how do I ...