You want to combine file I/O with conditional logic: Write a script that reads numbers from nums.txt and writes only even numbers to evens.txt. Which script snippet correctly does this?

hard🚀 Application Q9 of 15

Bash Scripting - File Operations in Scripts

You want to combine file I/O with conditional logic: Write a script that reads numbers from nums.txt and writes only even numbers to evens.txt. Which script snippet correctly does this?

Awhile read n; do if (( n % 2 == 0 )); then echo $n >> evens.txt; fi; done < nums.txt

Bfor n in $(cat nums.txt); do echo $n >> evens.txt; done

Ccat nums.txt | grep even > evens.txt

Decho $(cat nums.txt) > evens.txt

Step-by-Step Solution

Solution:

Step 1: Read numbers line by line from nums.txt
Using 'while read' safely processes each number.
Step 2: Use arithmetic condition to check even numbers
The condition (( n % 2 == 0 )) filters even numbers.
Step 3: Append even numbers to evens.txt
Using >> inside the if block adds only even numbers.
Final Answer:
while read n; do if (( n % 2 == 0 )); then echo $n >> evens.txt; fi; done < nums.txt -> Option A
Quick Check:
Combine file read and condition to filter output [OK]

Quick Trick: Use while read and if condition to filter file lines [OK]

Common Mistakes:

MISTAKES

Appending all numbers without filtering
Using grep incorrectly for even numbers
Overwriting file inside loop

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More Bash Scripting Quizzes

You want to combine file I/O with conditional logic: Write a script that reads numbers from nums.txt and writes only even numbers to evens.txt. Which script snippet correctly does this?

Step 1: Read numbers line by line from nums.txt

Step 2: Use arithmetic condition to check even numbers

Step 3: Append even numbers to evens.txt

Final Answer:

Quick Check:

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