[Solved] You have a log file with lines like:2024-06-01 ERROR Disk full 2024-06-01 INFO Backup started 2024-06-02 ERROR Network downWhich command extracts only the dates of ERROR lines? | Linux CLI

Linux CLI - Text Processing

You have a log file with lines like:

2024-06-01 ERROR Disk full
2024-06-01 INFO Backup started
2024-06-02 ERROR Network down

Which command extracts only the dates of ERROR lines?

Agrep 'ERROR' logfile | cut -d' ' -f3

Bgrep 'ERROR' logfile | awk '{print $1}'

Csed -n '/ERROR/p' logfile | cut -d' ' -f2

Dawk '/ERROR/ {print $2}' logfile

Step-by-Step Solution

Solution:

Step 1: Identify ERROR lines
grep 'ERROR' filters lines containing 'ERROR'.
Step 2: Extract date field
Date is the first field ($1), so awk '{print $1}' prints the date.
Final Answer:
grep 'ERROR' logfile | awk '{print $1}' -> Option B
Quick Check:
Filter ERROR then print first field = D [OK]

Quick Trick: Filter then print needed field for precise extraction [OK]

Common Mistakes:

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