19 lines
313 B
Bash
19 lines
313 B
Bash
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#!/usr/bin/env bash
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### 如果变量为空，赋给他们默认值
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: ${VAR:='default'}
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: ${1:='first'}
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echo "\$1 : " $1
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: ${2:='second'}
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echo "\$2 : " $2
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### 或者
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FOO=${FOO:-'default'}
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echo "FOO : " ${FOO}
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# execute: ./positionalVariableDemo.sh big small
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# output:
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# $1 : big
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# $2 : small
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# FOO : default
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