bash-variables.scroll

date 2010-0-18
tags index
permalink bash-variables.html
title Bash variables

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code
 $ FIVE=5
 $ echo $FIVE
 5
 $ echo "The number five is $FIVE"

# Variable scope

A shell script will launch a new shell that has a fresh scope.

code
 $ FIVE = 5
 $ vim myshellscript.sh
 #!/bin/bash
 echo $FIVE
 $ ./myshellscript.sh

Blank because the executed script doesn't affect the current shell. To make something affect the current shell, use the source command.

# Export command.

Use the export command to change the scope of your variable to global for your shell.

To make a permanent global variable, add it to your .bash_profile like so:

code
 MY_NAME=breck; export MY_NAME

# Accept input.

Use the read command to accept input.

code
 echo "What is 1+1?"
 read ANSWER
 echo "Your answer is $ANSWER"

# Notes

1. Bash <a href="https://steve-parker.org/sh/variables1.shtml
">tutorial</a> 2. Another <a href="https://www.mcsr.olemiss.edu/unixhelp/environment/env3db.html
">tutorial</a> 3. Bash <a href="https://steve-parker.org/sh/variables2.shtml
">parameters</a>
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