I cant really wrap my head around BOOLEAN logic when I use NOT together with AND and OR

Posted by Bq on Stack Overflow See other posts from Stack Overflow or by Bq
Published on 2010-04-29T09:24:16Z Indexed on 2010/04/29 9:27 UTC
Read the original article Hit count: 390

Filed under:

boolean-logic

|

awk

|

boolean-expression

|

boolean

Im trying to understand how boolean logic works when I use NOT. To give an example using awk

I have a text file containing

CORE
PORT
CORE 
PORT
COREPORT
CORE
COREPORT

And I would like to remove all COREPORT lines. The way I thought I would do it was with (NOT CORE) AND (NOT PORT) eg

awk '/!CORE/&&/!PORT/{print}'

But when I try it out Im actually supposed to use OR instead of AND

awk '/!CORE/||/!PORT/{print}'

I would be really glad if some one could explain where my thinking is wrong and super glad if it could be visualized with a venn diagram or something like the boolean machine at kathyschrock

© Stack Overflow or respective owner

Related posts about boolean-logic

How do I parse boolean logic?

as seen on Stack Overflow - Search for 'Stack Overflow'
I need to write a boolean logic parser which will translate the boolean logic language to a SQL WHERE clause. The order of the operands will always be in the correct order (with value on the right). Here is a relatively simple example. There could be nested parentheses and the use of NOT operators… >>> More
Dynamically evaluating simple boolean logic in Python

as seen on Stack Overflow - Search for 'Stack Overflow'
I've got some dynamically-generated boolean logic expressions, like: (A or B) and (C or D) A or (A and B) A empty - evaluates to True The placeholders get replaced with booleans. Should I, Convert this information to a Python expression like True or (True or False) and eval it? Create a binary… >>> More
Boolean logic parser for SQL

as seen on Stack Overflow - Search for 'Stack Overflow'
This is going to sound crazy but does anyone have techniques that would allow me to parse boolean logic strings in Sql Server 2005 without extraordinary/rediculous effort? Here is an example: (SOMEVAR=4 OR SOMEVAR=5) AND (NOT OTHERVAR=Y) I feel like recursion would help a lot if that were possible… >>> More
How to parse a string of boolean logic in PHP

as seen on Stack Overflow - Search for 'Stack Overflow'
I'm building a PHP class with a private member function that returns a string value such as: 'true && true || false' to a public member function. (This string is the result of some regex matching and property lookups.) What I'd like to do is have PHP parse the returned logic and have… >>> More
MySQL Stored Procedure: Boolean Logic in IF THEN

as seen on Stack Overflow - Search for 'Stack Overflow'
I'm looking for the proper syntax (if this is possible in MySQL stored procedures) for using logical operators in an IF THEN statement. Here's something along the lines of what I would like to do, but I'm not certain if I should type "OR" or "||" in the IF ... THEN clause: DELIMITER $$ CREATE PROCEDURE… >>> More

Related posts about awk

problem with awk script

as seen on Stack Overflow - Search for 'Stack Overflow'
Hello, when I call my awk script, I keep getting an error : sam@sam-laptop:~/shell/td4$ awk -f agenda.awk -- -n Robert agenda.txt awk: agenda.awk:6: printf "Hello" awk: agenda.awk:6: ^ syntax error the script contains this : #!/usr/bin/awk BEGIN { } printf "Hello" END { } Thank you >>> More
Awk to grab colo(u)r codes from CSS files aka School me in Awk

as seen on Stack Overflow - Search for 'Stack Overflow'
Nice and (hopefully) easy. I am trying to work out how to grab the variable #XXX from a text file (css file) containing strings like hr { margin: 18px 0 17px; border-color: #ccc; } h1 a:hover, h2 a:hover, h3 a:hover { color: #001100; } Which I would like to return as ccc 777 The… >>> More
Parsing the output of "uptime" with bash

as seen on Super User - Search for 'Super User'
I would like to save the output of the uptime command into a csv file in a Bash script. Since the uptime command has different output formats based on the time since the last reboot I came up with a pretty heavy solution based on case, but there is surely a more elegant way of doing this. uptime… >>> More
AWK scripting :How to remove Field separator using awk

as seen on Stack Overflow - Search for 'Stack Overflow'
Need the following output ONGC044 ONGC043 ONGC042 ONGC041 ONGC046 ONGC047 from this input Medium Label Medium ID Free Blocks =============================================================================== [ONGC044] ECCPRDDB_FS_43 ac100076:4aed9b39:44f0:0001… >>> More
sort associative array in awk - help?

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi all, I have an associative array in awk that gets populated like this... chr_count[$3]++ When I try to print my chr_counts I use this: for (i in chr_count) { print i,":",chr_count[i]; } But not surprisingly, the order of i is not sorted in any way. Is there an easy way to iterate over… >>> More