84 lines
1.1 KiB
Markdown
84 lines
1.1 KiB
Markdown
---
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title: "conditionals"
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tags: [ "Documentation", "basics" ]
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---
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# If statements
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Test statement equality as so:
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```
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read t1
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read t2
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if test $t1 != $t2; then
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echo 'variables do not match'
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else
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echo 'variables match'
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fi
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exit 0
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```
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# Case Structure
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These deal with multiple states rather than forking conditions.
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Example:
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```
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#!/bin/bash
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# Simple case demonstration
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echo "What's your favourite creature?"
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read CRE
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case $CRE in
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human | humanoids ) echo "Why is $CRE always standard?"
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;;
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troll | monsters ) echo "Not exactly known for their character ..."
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;;
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owlbears | monsters ) echo "Really you're a wizard fan"
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;;
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esac
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# While and Until
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This prints from 1 until 9.
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> COUNTER=1
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> while [ $COUNTER -lt 2 ]; do
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> ((COUNTER++))
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> echo $COUNTER
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> done
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```
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There's also 'until', which stops when something is true, rather than keeping going when something is true.
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# For
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> for i in $( ls ); do
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> du -sh $i
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> done
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# Sequences
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The sequences tool counts up from X in jumps of Y to number Z.
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Count from 1 to 10.
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> seq 10
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Count from 4 to 11.
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> seq 4 11
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Count from 1 to 100 in steps of 5.
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> seq 1 5 100
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