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1 <stránka |
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2 xmlns="https://trac.frantovo.cz/xml-web-generator/wiki/xmlns/strana" |
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3 xmlns:m="https://trac.frantovo.cz/xml-web-generator/wiki/xmlns/makro"> |
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4 |
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5 <nadpis>Using boolean logic with AWK</nadpis> |
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6 <perex>boolean data type and logical AND, OR, XOR operators</perex> |
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7 <m:pořadí-příkladu>02500</m:pořadí-příkladu> |
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8 |
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9 <text xmlns="http://www.w3.org/1999/xhtml"> |
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10 |
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11 <p>Expect that we have a relation with four combinations of logical values:</p> |
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12 |
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13 <pre><![CDATA[logic: |
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14 ╭─────────────┬─────────────╮ |
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15 │ a (boolean) │ b (boolean) │ |
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16 ├─────────────┼─────────────┤ |
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17 │ true │ true │ |
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18 │ true │ false │ |
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19 │ false │ true │ |
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20 │ false │ false │ |
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21 ╰─────────────┴─────────────╯ |
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22 Record count: 4]]></pre> |
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23 |
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24 <p> |
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25 we can use logical operators and functions: |
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26 </p> |
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27 |
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28 |
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29 <m:pre jazyk="bash"><![CDATA[relpipe-in-cli \ |
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30 generate logic 2 \ |
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31 a boolean \ |
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32 b boolean \ |
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33 true true \ |
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34 true false \ |
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35 false true \ |
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36 false false \ |
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37 | relpipe-tr-awk \ |
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38 --relation '.*' \ |
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39 --output-attribute AND boolean \ |
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40 --output-attribute OR boolean \ |
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41 --output-attribute XOR boolean \ |
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42 --input-attributes-prepend \ |
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43 --for-each '{ AND = a && b; OR = a || b; XOR = xor(a,b); record(); }' \ |
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44 | relpipe-out-tabular]]></m:pre> |
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45 |
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46 <p>and append their results to the relation as additional attributes:</p> |
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47 |
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48 <pre><![CDATA[logic: |
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49 ╭─────────────┬─────────────┬───────────────┬──────────────┬───────────────╮ |
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50 │ a (boolean) │ b (boolean) │ AND (boolean) │ OR (boolean) │ XOR (boolean) │ |
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51 ├─────────────┼─────────────┼───────────────┼──────────────┼───────────────┤ |
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52 │ true │ true │ true │ true │ false │ |
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53 │ true │ false │ false │ true │ true │ |
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54 │ false │ true │ false │ true │ true │ |
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55 │ false │ false │ false │ false │ false │ |
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56 ╰─────────────┴─────────────┴───────────────┴──────────────┴───────────────╯ |
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57 Record count: 4]]></pre> |
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58 |
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59 </text> |
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60 |
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61 </stránka> |