[Solved] What does the sed command sed 's/cat/dog/' file.txt do? — Ans: Replaces the first occurrence of 'cat' with 'dog' on each line of file.txt | Linux CLI

Linux CLI - Text Processing

What does the sed command sed 's/cat/dog/' file.txt do?

ADeletes all lines containing 'cat' in file.txt

BReplaces the first occurrence of 'cat' with 'dog' on each line of file.txt

CPrints only lines containing 'dog' from file.txt

DAppends 'dog' at the end of each line containing 'cat' in file.txt

Step-by-Step Solution

Solution:

Step 1: Understand the substitution command
The s/pattern/replacement/ syntax in sed replaces the first match of 'pattern' with 'replacement' on each line.
Step 2: Apply to the given command
The command replaces the first occurrence of 'cat' with 'dog' on every line of file.txt.
Final Answer:
Replaces the first occurrence of 'cat' with 'dog' on each line of file.txt -> Option B
Quick Check:
sed substitution = replace first match [OK]

Quick Trick: Remember: s/pattern/replacement/ changes first match per line [OK]

Common Mistakes:

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