awk command

awk command:

awk  -F ':'  '{print $#,$#}'   file_name

awk finds a single string and prints:

awk -F: '$1 ~ /n+/' passwd This means that column 1 matches a string containing n

$1 ~ /n+/ $1 means the first column  ~ means matching  /n+/ means a string containing n 

awk finds qualified (> < == != && || ):

awk displays line and column numbers, more exact match:

awk -F: '{OFS="#"} $3<10 {print $1,$3,$6}' passwd

awk -F: '{OFS="#"} {if($3<10) {print $1,$3,$6}}' passwd

awk -F: '{print NR,$0}' passwd

awk -F: 'NR<=3 {print $0}' passwd

awk -F:  'NR<=3 {print NR,$0}' passwd

 awk -F:  'NF==6  {print NF,$0}' passwd

awk -F:  'NR<=5 && $3==1  {print NR,$0}' passwd

awd to change the string:

awk -F: '{OFS=":"} $1="newname" {print $0 }' passwd

awk -F: '{all=(all+$3)};END {print all}' passwd

awk -F: '{all=all+$3};END {print all}' passwd

awk -F: 'all=all+$3;END {print all}' passwd