How to ignore invalid options in getopt_long

Question

I am using function getopt_long to get command line options. I want to ignore error when a invalid option is given. Currently it printing error to stderr like:

 invalid option -- 's'

Answer 1

There's variable opterr in unistd.h which will avoid printing the the error to stderr if you set it to 0.

Just set it to 0:

#include <unistd.h>

opterr = 0;