Linux/Environment Variables: Difference between revisions
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(Created page with "== Basics == * List all environment variables <blockquote> <pre> env printenv </pre> </blockquote> * get variable <blockquote> <pre> echo $USER printenv USER </pre> </blockquote> * set variable <blockquote> <pre> VARIABLE='Hello world' echo $VARIABLE </pre> </blockquote> * promote a shell variable to an environment variable <blockquote> <pre> export VARIABLE='Hello world' </pre> </blockquote> * variable lists <blockquote> <pre> export VARIABLE='Hello world':'test'...") |
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<blockquote> | <blockquote> | ||
<pre> | <pre> | ||
VARIABLE='Hello world':'test' # variable with two elements | |||
VARIABLE=$VARIABLE:'test2' # add another element | |||
</pre> | </pre> | ||
</blockquote> | </blockquote> | ||
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== Use in scripts == | == Use in scripts == | ||
* script.sh | |||
<blockquote> | |||
<pre> | |||
DATE='01-01-2000' | |||
export DATE | |||
export VARIABLE="123" | |||
</pre> | |||
</blockquote> | |||
[[Category:Linux/System]] | [[Category:Linux/System]] | ||
[[Category:Linux]] | [[Category:Linux]] | ||
Revision as of 11:29, 30 November 2023
Basics
- List all environment variables
env printenv
- get variable
echo $USER printenv USER
- set variable
VARIABLE='Hello world' echo $VARIABLE
- promote a shell variable to an environment variable
export VARIABLE='Hello world'
- variable lists
VARIABLE='Hello world':'test' # variable with two elements VARIABLE=$VARIABLE:'test2' # add another element
- remove variable
unset VARIABLE
Use in scripts
- script.sh
DATE='01-01-2000' export DATE export VARIABLE="123"