Linux Shell programming awk and linuxshell programming awk

Linux Shell programming awk and linuxshell programming awk

• Awk [-field-separator] 'commands' input-file (s)

Basic Mode

• Awk-F ':'...

Use # to separate

• Awk '{print $0}' a.txt

Print all

• Awk '{print $1, $3}' a.txt

Print 1st and 3 columns

• Awk 'in in {print "0"} {print $1} 'a.txt

Print 0 on the first line

• Awk '{print $1} END {print "0"}' a.txt

Print the last line 0

• Awk '$1 = "0" {print $0}' a.txt

Rows with the first column equal to 0

• Awk '$1! = "0" {print $0} 'a.txt

Rows in the first column not equal to 0

• Awk '$1 <= $2'

Rows in the first column smaller than or equal to the second column

• Awk '$0 !~ /0/'a.txt

RegEx matches all rows whose columns do not contain 0.

• Awk '$1 ~ /(12 | (34)/'a.txt

RegEx matches the first column with 12 or 34 rows.

• Awk 'if ($1> 1 & $2 <1) {print $1} a.txt

The first column of the row where the first column is greater than 1 and the second column is smaller than 1

• Awk 'if ($1> 1 | $2 <1) {print $2} a.txt

The second column of the First or Second column that is less than 1

• Awk '{print nf rs nr}' a.txt

Number of columns of records, record separator, and number of read records are printed consecutively.

• Awk 'nr = FNR {print $1} NR> FNR {print $2} 'a.txt B .txt

Print the first column of the First file and the second column of the Second file

• Awk '{$1 = $1*2; print $1}' a.txt

Modify numeric print

• Awk 'in in {LAST = 0} {if ($1> LAST) print $1; LAST = $1 }'

Compare and print the incremental series one by one

• Awk '{total + = $1} END {print total}' a.txt

Statistical column Value

• Awk '{printf "% c", $1}' a.txt

Format output

• Awk '{print match ($1, "1")}' a.txt

Print the position of the first 1 In the first column without printing 0

• Awk '{gsub (/AB/, "cd", $1); print $0}' a.txt

String replacement in the first column

• Awk '{MAP [$1] =2 2} END {for (I in MAP) {print I, MAP [I]}' a.txt

Dictionary storage and Extraction