Better way to Cleaning UP string variable

Here's what I found.

Tells me if it's optimize or not.

set TCP_Payload [string range [TCP::payload] [expr [string first "://" [TCP::payload]] + 3] [expr [string last ":" [TCP::payload]] - 1]]

I must use an expr cause the string first and string last return only the first index.

Any other suggestion would be appreciated

Both works

mine : set TCP_Payload [string range [TCP::payload] [expr [string first "://" [TCP::payload]] + 3] [expr [string last ":" [TCP::payload]] - 1]]

Sheigh : scan [TCP::payload] {%*[^/]//%[^:]} TCP_Payload

does the scan use regexp ? I heard that regexp is more cpu intensive.

I want to know which on is less CPU intensive ?

Thanks Sheigh for your output

Maybe I'm missing what your trying to do.

Here's another scan example:

% scan $string {%*[^:]://%[^:]} fqdn
1
% puts $fqdn
sub.domain.com

This will exclude everything up until '://' which it will also throw out. From there it will match the remaining string until the next instance of ':' is found and put that into the fqdn variable.

You didn't miss anything.

Both solution works. I just want to know which one is less cpu intensive.

Thanks

Quick time comparison of the two:

% time {  set fqdn [string range $string [expr [string first "://" $string] + 3] [expr [string last ":" $string] - 1]] } 10000
5.7755 microseconds per iteration
% time { scan $string {%*[^:]://%[^:]} fqdn } 10000
1.2681 microseconds per iteration