Linux小技巧之awk必知必会

Linux Shell 三剑客之一，废话不多说直接上干货。

目录

• 1. 指定分隔符
• 2.指定打印行数
• 3.打印最后一列
• 4.打印倒数第二列
• 5.匹配输出
• 6.if 判断
• 7.统计列总数值
• 8.时间格式转换

示例数据：

1. 指定分隔符

awk -F '|' '{print $1}' log.txt

# awk -F '|' '{print $1}' log.txt
tbname
=================================================================
tb_7456_cm1eM
tb_7456_cm1e0
tb_7456_1bg3J
tb_7456_1dXax
tb_7456_1b9ol
tb_7456_1bhdH
tb_7456_1eAYV
tb_7456_1fxkg
tb_7456_1fZRW
tb_7456_cm1ez
tb_7456_1bg3J
tb_7456_cm1hX
tb_7456_cm1ck
tb_7456_cm1ck
tb_7456_cm1ck

2.指定打印行数

awk -F '|' 'NR>2 {print $1}' log.txt

# awk -F '|' 'NR>2 {print $1}' log.txt
tb_7456_cm1eM
tb_7456_cm1e0
tb_7456_1bg3J
tb_7456_1dXax
tb_7456_1b9ol
tb_7456_1bhdH
tb_7456_1eAYV
tb_7456_1fxkg
tb_7456_1fZRW
tb_7456_cm1ez
tb_7456_1bg3J
tb_7456_cm1hX
tb_7456_cm1ck
tb_7456_cm1ck
tb_7456_cm1ck

3.打印最后一列

awk -F '|' 'NR>2 {print $NF}' log.txt

# awk -F '|' 'NR>2 {print $NF}' log.txt
        1532
          13
         209
       56556
        3334
        7611
       48109
           3
        1668
        7249
         145
          22
           6
           1
         506

4.打印倒数第二列

awk -F '|' 'NR>2 {print $(NF-1)}' log.txt

# awk -F '|' 'NR>2 {print $(NF-1)}' log.txt
     108
     350
     293
      57
     207
     316
      26
      27
     148
     203
      18
     480
      64
      20
     348

5.匹配输出

awk -F '|' '/cm1e/ {print $1}' log.txt

# awk -F '|' '/cm1e/ {print $1}' log.txt
tb_7456_cm1eM
tb_7456_cm1e0
tb_7456_cm1ez

6.if 判断

awk -F '|' '{if ($3<100) print $0 }' log.txt

# awk -F '|' '{if ($3<100) print $0 }' log.txt
tbname         | create_time             |     cols|        rows
=================================================================
tb_7456_1dXax  | 2023-03-21 05:38:44.400 |      57 |       56556
tb_7456_1eAYV  | 2023-03-21 03:50:16.347 |      26 |       48109
tb_7456_1fxkg  | 2023-03-21 03:50:15.484 |      27 |           3
tb_7456_1bg3J  | 2023-09-05 12:42:18.269 |      18 |         145
tb_7456_cm1ck  | 2023-09-05 02:03:43.843 |      64 |           6
tb_7456_cm1ck  | 2023-03-21 03:50:19.610 |      20 |           1

# awk -F '|' '/cm1/ {if ($3<100) print $1"\t"$3 }' log.txt
tb_7456_cm1ck         64
tb_7456_cm1ck         20

7.统计列总数值

awk -F '|' 'NR>2 {sum+=$3} END {print sum}' log.txt

# awk -F '|' 'NR>2 {sum+=$3} END {print sum}' log.txt
2665

8.时间格式转换

awk '{print strftime("%Y-%m-%d %T",1697848286)}'

# date +%s |awk '{print strftime("%Y-%m-%d %T",$1)}'
2023-10-21 08:32:44