[root@mhc regular]# last -n 2|awk '{print $1 " " $3}'
root :0
root :0
wtmp Wed
[root@mhc regular]# last -n 2|awk '{print $1 " lines:" NR " columes:" NF}'
root lines:1 columes:10
root lines:2 columes:10
lines:3 columes:0
wtmp lines:4 columes:7
[root@mhc regular]# cat /etc/passwd | awk '{FS=":"} $3 < 10 {print $1 " " $3}'
root:x:0:0:root:/root:/bin/bash
bin 1
daemon 2
adm 3
lp 4
sync 5
shutdown 6
halt 7
mail 8
[root@mhc regular]# cat /etc/passwd | awk '{FS=":"} NR==2 {print $1 " " $3}'
bin 1
[root@mhc regular]# cat /etc/passwd | awk 'BEGIN {FS=":"} $3 < 10 {print $1 " " $3}'
root 0
bin 1
daemon 2
adm 3
lp 4
sync 5
shutdown 6
halt 7
mail 8
[root@mhc regular]# cat pay.txt
Name 1st 2nd
aa 200 300
bb 250 550
[root@mhc regular]# cat pay.txt | awk 'NR==1{printf "%10s %10s %10s %10s
", $1, $2, $3, "Total"} NR>=2{total = $2 + $3
> printf "%10s %10d %10d %10.2f
", $1, $2, $3, total}'
Name 1st 2nd Total
aa 200 300 500.00
bb 250 550 800.00
[root@mhc regular]# cat a.sh
#!/bin/bash
cat pay.txt | awk 'NR==1{printf "%10s %10s %10s %10s
", $1, $2, $3, "Total"} NR>=2{total = $2 + $3
printf "%10s %10d %10d %10.2f
", $1, $2, $3, total}'
[root@mhc regular]#
[root@mhc regular]#
[root@mhc regular]# ./a.sh
Name 1st 2nd Total
aa 200 300 500.00
bb 250 550 800.00