How to remove a particular substring from a string?

Question

In my C++ program, I have the string

string s = "/usr/file.gz";

Here, how to make the script to check for .gz extention (whatever the file name is) and split it like "/usr/file"?

Answer 1

You can use erase for removing symbols:

str.erase(start_position_to_erase, number_of_symbols);

And you can use find to find the starting position:

start_position_to_erase = str.find("smth-to-delete");

Answer 2

How about:

// Check if the last three characters match the ext.
const std::string ext(".gz");
if ( s != ext &&
     s.size() > ext.size() &&
     s.substr(s.size() - ext.size()) == ".gz" )
{
   // if so then strip them off
   s = s.substr(0, s.size() - ext.size());
}