Beginner LevelLinux Commands & SysAdmin
How does awk process space/comma-delimited text columns (print $1, $2)?
❓ Interview Prompt: Explain awk pattern-scanning language, field variables ($1, $2, $0), custom field separators (-F), and line filtering.
'awk' is a powerful pattern-scanning and data processing language that operates on field-delimited columns:
Key Field Variables:
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'$0': Entire line text.
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'$1', '$2', '$3': 1st, 2nd, and 3rd delimited fields.
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'-F","': Specifies custom field separator (e.g. comma for CSV files).
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'NR': Current row number | 'NF': Number of fields in current row.
Code Implementation Example
bash
# Print 1st (username) and 7th (shell) columns from /etc/passwd using ':' separator
awk -F":" '{print $1, $7}' /etc/passwd
# Filter processes using more than 10% CPU from ps aux output
ps aux | awk '$3 > 10.0 {print $2, $3, $11}'💡Extracting specific text columns and filtering data using awk.
🎯 Interview Key Takeaway
Use awk -F for field-delimited column extraction and inline condition filtering.
#awk#Text Processing#Columns#Beginner
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