Ravi Sir's Cards › AWS
[ ] vs [[ ]]?
What is a VPC: your own private network inside one AWS Region, example ThreeTierVpc 10.0.0.0/16.
![[ ] vs [[ ]]? [ ] is POSIX test. [[ ]] is bash: safer, patterns, regex. Regex.](/aws/ravi-sirs-cards/cards/en/int-lx7-int-brackets.webp)
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What this card says
What it is
[ ] is POSIX test.
Why it matters
[[ ]] is bash: safer, patterns, regex.
How / example
Regex.
[[ $v =~ ^[0-9]+$ ]]