[Solved] Consider the script snippet: var="abc123abc456" echo ${var##abc*} It outputs an empty line. Why? - Ans: Because abc* matches the longest prefix, so nothing remains | Bash Scripting

Bash Scripting - String Operations

Consider the script snippet:

var="abc123abc456"
echo ${var##abc*}

It outputs an empty line. Why?

ABecause the pattern is invalid and causes an error

BBecause <code>abc*</code> matches the entire string as shortest prefix

CBecause <code>abc*</code> matches the longest prefix, so nothing remains

DBecause the variable is empty

Step-by-Step Solution

Solution:

Step 1: Analyze the pattern abc*
The pattern abc* matches 'abc' followed by zero or more any characters.
Step 2: Understand longest prefix removal
With ##, it removes the longest matching prefix. The * matches greedily as many characters as possible after 'abc', so the match covers the entire string.
Final Answer:
Because abc* matches the longest prefix, so nothing remains -> Option C
Quick Check:
Longest prefix with ## + greedy * = B [OK]

Quick Trick: Wildcard * matches greedily with longest prefix ## [OK]

Common Mistakes:

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