How to use std::string as command with the system() call?

Question

I am trying to pass a string into the system() shell command function. I am trying to pass a concatenated string into it like so:

string parameters = "Doug";
system("ps -ef|grep " + parameters);

It keeps giving me error because system() takes a char*. How would I go about having the system() function work. I tried putting parameters.c_str() but doesn't work. Thanks!

Answer 1

You need to call c_str() on the result of the concatenation:

system(("ps -ef|grep " + parameters).c_str());

(Note the parentheses.)