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netadmindetail_'s avatar
netadmindetail_
Icon for Nimbostratus rankNimbostratus
Apr 22, 2015
Solved

Better way to Cleaning UP string variable

Hi all   I must use the destination FQND of a TCP connection. I'm able to collect the TCP payload but I need to compare it with a data-class. But before doing that I need to clean the TCP payloa...
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  • Sheigh_65772's avatar
    Sheigh_65772
    Apr 22, 2015

    How about using scan?

    If the variable string is set '9net.tcp://sub.domain.com:12345/abcdefg' or 'sometotherstuff9net.tcp://sub.domain.com:12345/abcdefg/lkjsdflkj/sdfl' etc then try using

    scan $string {%*[^/]//%[^:]} fqdn

    this results in a new variable $fqdn of 'sub.domain.com'

    You can test it out by using the tclsh

    % set string "lkasdflkjwe234239net.tcp://sub.domain.com:12345/abcdefg/sdlfkjasf"
lkasdflkjwe234239net.tcp://sub.domain.com:12345/abcdefg/sdlfkjasf
% puts $string
lkasdflkjwe234239net.tcp://sub.domain.com:12345/abcdefg/sdlfkjasf

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

    Check out this link: https://devcentral.f5.com/articles/irules-101-18revisiting-the-tcl-scan-command

    FYI I'm just starting to play with scan so YMMV.

    Sheigh

Sheigh_65772's avatar
Sheigh_65772
Icon for Cirrus rankCirrus
Apr 22, 2015

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
  • netadmindetail_'s avatar
    netadmindetail_
    Icon for Nimbostratus rankNimbostratus
    Apr 22, 2015
    Wow, thank you very much for this kind of output. Can you tell me how you've been able to grab this information ? Is this the time keyword ? how do you stop the timer ?
  • Sheigh_65772's avatar
    Sheigh_65772
    Icon for Cirrus rankCirrus
    Apr 22, 2015
    So that was all from within the tclsh shell. From your f5 device just type tclsh and you'll drop in. The time command just takes what you want to run and runs it the number of times you specify: time { your commands } itterations