Parameter Expansion (Advanced)

Advanced~30 min read

Perform powerful string manipulations using slicing, pattern trimming, and substitutions all within the shell.

Slicing and Trimming

Output

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Note: These expansions are POSIX/Bash features; exact behavior can vary by shell.

Pro Tip: Use braces around variables (e.g., ${name}) when concatenating to avoid ambiguity.

Caution: Pattern matching uses globs, not full regex. Use character classes and *, ? patterns.

Parameter expansion patterns are glob-like, not regular expressions.

Remember slicing is zero-based: ${s:0:1} is the first character.

Task: Given path=/var/log/nginx/access.log, echo the directory and the basename without extension using parameter expansion only.

Output

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Show Solution

echo "${path%/*}"; base="${path##*/}"; echo "${base%.*}"

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