[英]Linux differences between consecutive lines
I need to loop trough n
lines of a file and for any i between 1 and n - 1
to get the difference line(n - 1) - line(n)
. 我需要循环通过文件的
n
行和i between 1 and n - 1
任何i between 1 and n - 1
来获得差异line(n - 1) - line(n)
。
And here is the source file: 这是源文件:
root@syncro:/var/www# cat cron.log | grep "/dev/vda"
/dev/vda 20418M 14799M 4595M 77% /
/dev/vda 20418M 14822M 4572M 77% /
/dev/vda 20418M 14846M 4548M 77% /
/dev/vda 20418M 14867M 4527M 77% /
/dev/vda 20418M 14888M 4506M 77% /
/dev/vda 20418M 14910M 4484M 77% /
/dev/vda 20418M 14935M 4459M 78% /
/dev/vda 20418M 14953M 4441M 78% /
/dev/vda 20418M 14974M 4420M 78% /
/dev/vda 20418M 15017M 4377M 78% /
/dev/vda 20418M 15038M 4356M 78% /
root@syncro:/var/www# cat cron.log | grep "/dev/vda" | cut -b 36-42 | tr -d " M"
4595
4572
4548
4527
4506
4484
4459
4441
4420
4377
4356
those /dev/vda...
lines are logged hourly with df -BM
in cron.log
file and the difference between lines will reveal the hourly disk consumption. 这些
/dev/vda...
行每小时用cron.log
文件中的df -BM
记录,行之间的差异将显示每小时磁盘消耗。
So, the expected output will be: 所以,预期的产出将是:
23 (4595 - 4572)
24 (4572 - 4548)
...
43 (4420 - 4377)
21 (4377 - 4356)
I don't need the text between (
and )
, I put it here for explanation only. 我不需要
(
和)
之间的文本,我把它放在这里只是为了解释。
I'm not sure if I got you correctly, but the following awk
script should work: 我不确定我是否正确,但以下
awk
脚本应该工作:
awk '{if(NR>1){print _n-$4};_n=$4}' your.file
Output: 输出:
23
24
21
21
22
25
18
21
43
21
You don't need the other programs in the pipe. 您不需要管道中的其他程序。 Just:
只是:
awk '/\/dev\/vda/ {if(c++>0){print _n-$4};_n=$4}' src/checkout-plugin/a.txt
will be enough. 就足够了。 The regex on start of the
awk
scripts tells awk to apply the following block only to lines which match the pattern. 启动
awk
脚本的正则表达式告诉awk仅将以下块应用于与模式匹配的行。 A side effect is that NR
can't be used anymore to detect the "second line" in which the calculation starts. 副作用是
NR
不能再用于检测计算开始的“第二行”。 I introduced a custome counter c
for that purpose. 我为此目的介绍了一个客户柜台
c
。
Also note that awk
will remove the M
on it's own, because the column has been used in a numeric calculation. 另请注意,
awk
会自行删除M
,因为该列已用于数值计算。
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.