How do I declare a constant in shell script?

BashShell

Bash Problem Overview

I can't find this information from the internet, is it not possible to declare a final constant variable whose value will not change after first initialization?

Bash Solutions

Solution 1 - Bash

I believe you can do something like:

readonly DATA=/usr/home/data/file.dat

You can also do:

declare -r var=123

Solution 2 - Bash

http://gnu.org/software/bash/manual/bashref.html#index-readonly-119">readonly</a> FOO=bar

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Solution 3 - Bash

In bash you can mark a variable read only by declaring it via the builtin readonly like so:

readonly CONSTVAR=value
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Content TypeOriginal AuthorOriginal Content on Stackoverflow
QuestionOh Chin BoonView Question on Stackoverflow
Solution 1 - BashdiagonalbatmanView Answer on Stackoverflow
Solution 2 - BashAnders LindahlView Answer on Stackoverflow
Solution 3 - Bashal.View Answer on Stackoverflow