The AWK Command – Complete Guide
AWK is a Unix text-processing language for scanning structured text files line-by-line and performing actions on matching patterns.
It is commonly used for logs, CSV files, reports, and automation pipelines.
It is commonly used for logs, CSV files, reports, and automation pipelines.
Each line is split into fields: $1, $2, $3…
$0 represents the entire line.
Default delimiter: whitespace (FS variable).
Built-in variables:
$0 represents the entire line.
Default delimiter: whitespace (FS variable).
Built-in variables:
- NR – line number
- NF – number of fields
- FS – field separator
- OFS – output separator
awk 'pattern { action }' file
Examples:
awk '{print $1}' file
awk -F, '{print $2}' data.csv
awk '$3 > 100 {print}' report.txt
BEGIN runs before input starts.
END runs after all lines processed.
END runs after all lines processed.
awk 'BEGIN{print "Start"} {sum+=$2} END{print sum}' data.txt
Sum a column:
awk '{sum+=$2} END{print sum}' sales.txt
Filter logs:
awk '/error/ {print}' system.log
Top IP addresses:
awk '{print $1}' access.log | sort | uniq -c | sort -nr | head
• Installed on every Unix/Linux system
• Extremely fast (written in C)
• No dependencies
• Perfect for shell automation
• Replaces many small scripts
AWK is often described as SQL for text files.
• Extremely fast (written in C)
• No dependencies
• Perfect for shell automation
• Replaces many small scripts
AWK is often described as SQL for text files.