gistfile1.txt

use 5.10.00;
my $str = "urn:ietf:params:oauth:grant-type:jwt-bearer";
my $str2 = "urn:ietf-params-oauth:grant-type:jwt-bearer";
my $str3 = "urn:ietf:params:oauth:grant-type:jwt-bearer";
my $str4 = "urn:ietf-params-oauth:grant-type:jwt-bearer";
my $pattern = '^A-Za-z0-9\-._~!$\'()*,:@/?';
my $pattern2 = '\^A-Za-z0-9\-._~!$\'()*,:@/?';
$str =~ s/([$pattern])/sprintf '%%%02X', ord $1/ge;
$str2 =~ s/([$pattern])/sprintf '%%%02X', ord $1/ge;
$str3 =~ s/([$pattern2])/sprintf '%%%02X', ord $1/ge;
$str4 =~ s/([$pattern2])/sprintf '%%%02X', ord $1/ge;

say $str;
say $str2;
say $str3;
say $str4;