Awk

Extract fields and summarize text with small, readable programs.

Fields and separators

awk '{print $1}' file.txtPrint the first whitespace-separated field

awk -F, '{print $2}' data.csvSplit simple comma-delimited text; not a full CSV parser

awk '{print NR, $0}' file.txtPrefix each record with its number

awk '{print NF}' file.txtCount fields on each record

awk '/error/' app.logPrint matching records

awk 'NR > 1' data.txtSkip the first record

awk '$3 > 100' data.txtSelect by a numeric field

awk 'length($0) > 80' file.txtFind long lines

awk '{total += $2} END {print total}' data.txtSum the second field

awk 'END {print NR}' file.txtCount records

awk '{count[$1]++} END {for (k in count) print k, count[k]}' data.txtCount records by first field

awk 'BEGIN {OFS=","} {print $1,$2}' data.txtSet the output field separator