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beefy80's avatar
beefy80
Icon for Nimbostratus rankNimbostratus
Jun 05, 2014

Convert string with parity to standard ASCII

Hello

 

I need to convert a string that has Even Parity added to it to printable ascii. However I am having problems in getting this working. Can anyone advise on how to achieve this in an iRule.

 

Thanks

 

James

 

2 Replies

  • James_Deucker_2's avatar
    James_Deucker_2
    Historic F5 Account

    Here's the TCL that will do the encode

    set plain_str "james was here ok"
    puts "Plain String '$plain_str'"
    set even_parity ""
    foreach c [split $plain_str ""] { append even_parity [format %c [expr { ( [scan $c %c] & 127 ) + (!([scan $c %c] & 1)<<7)}]]}
    puts "Even Parity '$even_parity'"
    

    And here's the decode:

    set stripped_parity ""
    foreach c [split $even_parity ""] { append stripped_parity [format %c [expr {[scan $c %c] & 127}]]}
    puts "Stripped Parity '$stripped_parity'"
    

    Output:

    Plain String 'james was here ok'
    Even Parity 'êames was èeòe ok'
    Stripped Parity 'james was here ok'
    
  • James, Thank you for this I have been trying all sorts of variations to resolve this I wasn't far off getting it right either. Thanks again.