Interview › Scripting (Bash, Groovy)
How do you replace text in a variable using parameter expansion? [Intermediate]
Answer
Bash can replace text in a variable using ${var/pattern/replacement} for the first match and ${var//pattern/replacement} for all matches. The pattern is a shell pattern, not a full regex.
Technical explanation
This is useful for lightweight string normalization without spawning sed.
Use # or % anchored variants for prefix or suffix replacements.
For regex-based replacements or file edits, use sed, awk, Perl, or another appropriate tool.
Hands-on example
image="registry.local/orders-api:latest"
echo "${image/latest/$(git rev-parse --short HEAD)}"
name="feature/add login"
safe="${name//[^a-zA-Z0-9._-]/-}"
echo "$safe
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